1. Source of Bioelectric potential is ____________ in nature.

a) electronic
b) electric
c) ionic
d) mechanical
View Answer
Answer: c
Explanation: Bioelectric potentials are generated at cellular level and the source of these
potentials is ionic in nature. The prominent ions are K +, Na+, and Cl–. Electronic potential is
seen in commonly used cells for example the Galvanic cell. Mechanical potential is found
nowhere. Electrical potential is found in electricity.
2. Palsied muscles mean _____________
a) paralyzed muscles
b) active muscles
c) voluntary muscles
d) involuntary muscles
View Answer
3. The principal ion that is not involved with the phenomena of producing cell potentials is
______________
a) sodium
b) potassium
c) chlorine
d) hydrogen
View Answer
Answer: d
Explanation: Sodium (Na+), Potassium (K+), and Chlorine (Cl–) are the principal ions involved
with the phenomena of producing cell potentials. Na+ is present outside the cell membrane
and creates a positively charged environment outside the cell membrane. Cl – is present
inside the cell membrane and is responsible for the negative environment inside the cell
membrane.
4. What is the relatively static membrane potential of quiescent cells called?
a) half-cell potential
b) action potential
c) resting membrane potential
d) cell potential
View Answer
Answer: c
Explanation: Resting membrane potential or the resting potential is the relative static
membrane potential of quiescent cell. That is if the resting membrane potential of a neuron
is about -70 mV (mV=millivolt) it means that the inside of the neuron is 70 mV less than the
outside of the neuron. An action potential occurs when the potential of the membrane of a
given axonal position increases and decreases rapidly. This depolarization causes
depolarization of adjacent positions in a similar way.
5. The variation of the electrical potential associated with the passage of a pulse along the
membrane of a muscle cell or a nerve cell is called __________
a) muscle potential
b) action potential
c) resting potential
d) half cell potential
View Answer
Answer: b
Explanation: An action potential occurs when the potential of the membrane of a given
axonal position increases and decreases rapidly. This depolarization causes depolarization
of adjacent positions in a similar way. Resting membrane potential or the resting potential is
the relative static membrane potential of a quiescent cell.
6. Cells depolarize and action potential in generated as soon as a stimulus is applied.
a) True
b) False
View Answer
Answer: b
Explanation: This statement is False. This is because unless a stimulus above a certain
minimum value is applied, the cell will not be depolarized and no action potential will be
generated. This value of potential above which the depolarizes and an action potential is
generated is known as the stimulus threshold.
7. After a cell is stimulated, a finite period of time is required for the cell to return to its pre-
stimulus state. This period is known as ____________
a) restoration period
b) refactory period
c) regain period
d) regenerative period
View Answer
8. Electrooculography (EOG/E.O.G.) is a technique for measuring what?
a) abnormal function of the retina
b) heart rate
c) respiration rate
d) cornea-retinal standing potential
View Answer
Answer: d
Explanation: Electrooculography (EOG / E.O.G) is a technique for measuring the potential
of the corneal retinal standing potential that exists between the front and back of the human
eye. The resulting signal is called electrooculogram. The main applications are in the
diagnosis of ophthalmology and the recording of eye movements.
9. EKG stands for _________________
a) Electrocardiography
b) Electroencephalography
c) Electromyography
d) Electrtokinetcography
View Answer
Answer: a
Explanation: Electrocardiography (ECG or EKG) is the way toward recording the electrical
action of the heart over some stretch of time utilizing anodes put on the skin. It could simply
be understood as the electrical representation of heart beat. Electroencephalography is the
electrical recording of brain.
10. Phonocardiography is listening to __________
a) arm muscle sound
b) lungs sound
c) heart sound
d) respiratory tract sound

1. Electrodes make a transfer from the __________ in the tissue to the electronic
conduction which is necessary to make measurements.
a) electronic conduction
b) ionic conduction
c) electric conduction
d) impulsive conduction
View Answer
Answer: b
Explanation: Electrodes make an exchange from the ionic conduction in the tissue to the
electronic conduction which is important to make measurements. An electrolytic paste is
applied between the electrodes and the skin to reduce skin contact impedance. The
electrolyte also facilitates ionic conduction from the skin to the electrodes.
2. Surface electrodes damage the living tissues.
a) True
b) False
View Answer
Answer: b
Explanation: The surface electrodes pick up the potential difference from the tissue surface
when placed over it without damaging the living tissues. They are placed above the skin
and cause no harm to the living tissues. They capture the electrical activities of bunch of
tissues together.
3. Deep-seated electrodes indicates the electric potential difference arising ________ the
living tissues or cells.
a) inside
b) outside
c) around
d) adjacent
View Answer
Answer: a
Explanation: Deep-seated electrodes indicate the electric potential difference arising inside
the living tissues or cells. Surface electrodes indicates the electric potentials arising outside
the living tissues that is on the surface of the skin. Needle electrodes are example of deep
seated electrodes.
4. Impedance pneumography is a commonly-used technique to monitor a person’s _______
a) respiration rate
b) heart rate
c) pulse rate
d) skin impedance
View Answer
Answer: a
Explanation: Impedance pneumography is a commonly-used technique to monitor a
person’s respiration rate, or breathing rate. It is implemented by using two electrodes or four
electrodes. Skin impedance is the resistance between the skin and the electrode. Heart rate
measurement is called ECG.
5. Electrode paste ____________
a) increases contact impedance
b) equates contact impedance
c) reduces contact impedance
d) absorbs contact impedance
View Answer
Answer: c
Explanation: In order to obtain a clearly established contact (low contact impedance) an
electrolyte or electrode paste is usually employed as an interface between the electrode
and the surface of the source of the event. It is placed between the skin and the electrode. It
helps to get better signal acquisition.
6. All electrode potentials are measured with respect to which reference electrode?
a) hydrogen electrode
b) platinum electrode
c) calomel electrode
d) hydrogen absorbed on platinum electrode
View Answer
Answer: d
Explanation: All electrode potentials are measured with respect to a reference electrode,
usually that of hydrogen absorbed on platinum black. Thus, considering potential of
hydrogen absorbed on platinum electrode to be zero, other all have positive of negative
potentials.
7. What is the frequency range of ECG?
a) 70-120 Hz
b) 0.05-120 Hz
c) 5-120 Hz
d) 12-120 Hz
View Answer
Answer: b
Explanation: Primary signal characteristics of ECG are:
Frequency range: 0.05-120 Hz.
Signal amplitude: 0.1-5 mV.
Typical signal: 1mV.
8. What is the signal amplitude of EEG?
a) 2-200 µV
b) 2-200mV
c) 2-2000 µV
d) 2-2000mV
View Answer
Answer: a
Explanation: The signal amplitude of EEG is between 2-200 µV. It is very small and requires
special type of electrodes namely scalp electrodes. EEGs are difficult to capture because its
signal range in very small and motion artifacts are much greater.
9. Needle electrode is used to measure ____________
a) EKG
b) EEG
c) EOG
d) EMG
View Answer
Answer: d
Explanation: EMG stands of Electromyogram. For recording action potential for individual
motor units of muscle fiber, needle electrodes are used for better diagnostic information.
These electrodes fall in the category of deep seated electrodes.
10. From equipment point of view, the respiratory system in the human body is a
_________ system.
a) hydraulic
b) pneumatic
c) mechanical
d) electrical
View Answer
Answer: b
Explanation: Respiratory system is a pneumatic system in which an air pump (diaphragm)
alternately creates negative and positive pressures in a sealed chamber (thoracic cavity)
and causes air to be sucked into and forced out of a pair of elastic bags (lungs). Blood
circulatory system is related to hydraulic system.
11. Off-set potential is _____________
a) difference in half-cell potentials between two electrodes
b) sum of half-cell potentials between two electrodes
c) average of half-cell potentials between two electrodes
d) complement of half-cell potentials between two electrodes
View Answer
Answer: a
Explanation: The difference in half cell potential that exists between two electrodes is called
off-set potential. The differential amplifies used to measure potentials between two
electrodes are generally designed to cancel the electrode offset potential so that only the
signals of interest are recorded.
12. Which of the following is not preferred for electrode making?
a) Ag-AgCl
b) Copper
c) Stainless-steel
d) Gold
View Answer
Answer: c
Explanation: Stainless steel in contact with a saline electrolyte produce a potential
difference of 10 mV between the electrodes which is much more than the limit (i.e 2.5 mV).
Ad-AgCl electrodes give almost noise free characteristics. They are also found to be
acceptable from the point of view of long term drift.
13. Which of the following statement is false about polarizable electrodes?
a) they are made using stainless steel
b) used for recording resting ECG
c) retain a residual charge when exposed to large pulse of energy
d) can transmit small bioelectric signals even after getting exposed to large pulse of energy
View Answer
Answer: d
Explanation: Polarizable electrodes usually employ stainless steel and are used for resting
ECG or other situations where there is small likelihood that the electrode would be exposed
to a large pulse of energy (such as defibrillation discharge) in which case they would retain
a residual charge, become polarized, and will no longer transmit the relatively small
bioelectric signals, thus become useless.
14. Which electrodes can work even after being induced to large electric discharge such as
defibrillation?
a) polarizing electrodes
b) magnetic electrodes
c) non-polarizing electrodes
d) electrolytic electrodes
View Answer
Answer: c
Explanation: Non-polarizing electrodes are designed to rapidly dissipate any charge
imbalance induced by powerful electric discharges such as a defibrillation procedure. Rapid
depolarization enables the immediate reappearance of bioelectric signals on the monitor
after defibrillation. For this reason, non-polarizing electrodes have become the electrodes of
choice for monitoring in the intensive care units and stress testing procedures.
1. Which type of electrodes are employed to study the electrical activities of individual cells?
a) milli-electrodes
b) micro-electrodes
c) surface-electrodes
d) pre-jelled electrodes
View Answer
Answer: b
Explanation: To study the electrical activities of individual cells, micro electrodes are
employed. This type of electrode is small enough with respect to the size of the cells.
Typical micro electrodes have tip dimensions ranging from 0.5-5 microns.
2. Glass micro-capillaries are a type of micro electrode.
a) True
b) False
View Answer
Answer: a
Explanation: Two types of micro electrodes are generally used: metallic and glass
microcapillaries. Metallic electrodes are formed from a fine needle of suitable metal drawn
for a fine tip. Glass electrodes are drawn from Pyrex glass of special grade.
3. Glass microcapillaries are preferred over metallic electrodes because of the former
_______
a) polarizes with input current
b) does not have sustainable current carrying capacity
c) has less contact surface area
d) has sustainable current carrying capacity
View Answer
Answer: d
Explanation: Metallic electrodes polarize with smaller amplifier input currents. Hence, they
tend to develop unstable electrode offset potential and are therefore not preferred for steady
state potential measurement. On the other hand, in case of glass micro electrodes have a
sustainable current carrying capacity because of the large surface area between the metal
and the electrolyte.
4. Do metallic micro electrodes exist.
a) True
b) False
View Answer
Answer: a
Explanation: Two types of micro electrodes are generally used: metallic and glass
microcapillaries. Metallic electrodes are formed from a fine needle of suitable metal drawn
for a fine tip. Glass electrodes are drawn from Pyrex glass of special grade.
5. Metallic micro electrodes have impedance ________ compared to conventional
electrodes?
a) equal
b) smaller
c) high
d) very high
View Answer
Answer: d
Explanation: The very high impedance of the metal micro-electrodes is due to the
characteristics of the small area metal-electrolyte interface. Because of very high
impedance of micro electrodes, amplifiers with extremely high input impedance are required
to avoid loading the circuit and to minimize the effects of small change in interface
impedance.
6. Which of the following electrode is manufactured by circumferential application of heat to
a small area of glass tubing and pulling the glass when it gets soft?
a) macro metallic electrodes
b) micro metallic electrodes
c) micro pipette
d) surface electrodes
View Answer
Answer: c
Explanation: The most commonly used method for making small tip micropipette consists of
the circumferential application of heat to a small area of glass tubing which is placed under
some initial tension. When the glass softens, the tension is increased very rapidly and the
heat is turned off. Proper timing, controlled adjustment of the amount of heat as well as the
initial and final tensions and cooling results in the production of microcapillaries with control
dimensions.
7. Which of the following metal is preferred for manufacturing micro electrodes?
a) Stainless steel
b) Tungsten
c) Iron
d) Copper
View Answer
Answer: b
Explanation: Tungsten is preferred for constructing micro-electrodes due to its mechanical
strength and its apparent inertness. Although tungsten itself is reactive, a surface layer of
tungsten oxide will, in most situations, protect the metal against corrosion.
8. ________________ are devices which convert one form of energy into another.
a) transducers
b) electrodes
c) impulses
d) opamp
View Answer
Answer: a
Explanation: Transducers are devices which convert one form of energy into another. A
number of factors decide the choice of a particular transducer to be used for the study of a
specific phenomenon. Many physical, chemical and optical properties and principles can be
applied to construct transducers for applications in the medical field.
1. Which of the following is a preferred electrode for measuring EMG?
a) surface electrodes
b) needle electrodes
c) pregelled electrodes
d) scalp electrodes
View Answer
Answer: b
Explanation: Electrodes for EMG work are usually of the needle type. Needle electrodes are
used in clinical EMG, neurography and other electrophysiological measurements of the
muscle tissues underneath the skin. Surface electrodes are preferred to measure ECG.
Scalp electrodes for EEG.
2. Generally what is the material of needle electrodes?
a) stainless steel
b) copper
c) lead
d) iron
View Answer
Answer: a
Explanation: The material of the needle electrode is generally stainless steel. In spite of the
face that stainless steel is unfavorable electrode material from the point of view of noise, it
is preferred in EMG work. It is due to its mechanical solidity and low price.
3. Monopolar needle electrodes are having coatings of which material over the stainless
steel wires which are bare only at the tips?
a) carbon
b) calcium
c) sodium
d) teflon
View Answer
Answer: d
Explanation: The monopolar needle electrode consists of a teflon coated stainless steel
wire. The wire is bare only at the tip. It is found that after the needle has been used a
number of times, the teflon coating will recede, increasing the tip area. The needle should
be discarded when this happens.
4. Which electrode can be used to pick up signals from individual fibers of muscle tissues?
a) biopolar needle electrode
b) concentric core needle electrode
c) multi-element needle electrode
d) monopolar needle electrode
View Answer
Answer: c
Explanation: Multi-element needle electrodes are used to pick up the signals from individual
fibers of muscle tissue. Special needles are available using 25-micron diameter electrode
surfaces. They have up to 14 pickup surfaces down the side of one needle.
5. _______________ instrument is used to hold patients head and guide the placement of
electrodes.
a) Monotaxic
b) Stereotonic
c) Stereotaxic
d) Monotonic
View Answer
Answer: c
Explanation: For measurement of potential from specific part of the brain, longer needles
are inserted inside the head. The needles are precisely located by means of a map or atlas
of the brain. A special instrument called stereotaxic instrument is used to hold the subject’s
head and guide the placement of the electrodes.
6. Number of cloud deployment models that are recognized are _________
a) 2
b) 5
c) 3
d) 4
View Answer
Answer: c
Explanation: There are 3 recognized cloud deployment models. They are – Private cloud,
Public cloud and Hybrid cloud.
7. The ground electrode is usually positioned over which body structures?
a) bony
b) hairy
c) fleshy
d) sweaty
View Answer
8. When intramuscular EMG is required to look into the electrical activities of deeper or
overlaid muscles, ________ electrodes are used.
a) plate shape electrodes
b) surface electrodes
c) thin thread electrodes
d) fine wire electrodes
View Answer
Answer: d
Explanation: When intramuscular EMG is required to look into the electrical activities of
deeper or overlaid muscles, thin and flexible fine wire electrodes are used. These
electrodes are inserted into the muscle site of interest. The needle or steel cannula is
removed, and the electrode wires are connected to the steel spring adapters to minimize
movement artefacts.
9. The contraction of the skeletal muscles results in the generation of action potential in the
individual muscle fibers. Record of this action potential is called ______________
a) ECG
b) EMG
c) EEG
d) EKG
View Answer
Answer: b
Explanation: The contraction of the skeletal muscles results in the generation of action
potential in the individual muscle fibers, a record of such action potential is known as
electromyogram (EMG). The activity is similar to that observed in the cardiac muscles (ECG
or EKG), but in the skeletal muscles, repolarization takes place much more rapidly. The
action potential lasts for only few milliseconds.
10. In voluntary contraction of the skeletal muscles, the muscle potential ranges from
________
a) 50 uV – 5 mV
b) 50 mV – 5 V
c) 0.05 uV – 2 mV
d) 50 mV – 500 mV
View Answer
Answer: a
Explanation: In voluntary contraction of the skeletal muscles, the muscle potential ranges
from 50 uV – 5 mV and duration from 2 to 15 ms. The values vary with the anatomic
position of the muscle and the size and location of the electrode. In a relaxed muscle there
are no action potentials.
This set of Biomedical Instrumentation Multiple Choice Questions & Answers (MCQs)
focuses on “Preamplifiers”.

1. Which amplifier will reject any common mode signal that appears simultaneously at both
amplifier input terminal and amplifies only the voltage difference that appears across its
input terminals?
a) ac coupled amplifiers
b) differential amplifiers
c) carrier amplifiers
d) dc amplifiers
View Answer
Answer: b
Explanation: Differential amplifier is one which will reject any common mode signal that
appears simultaneously at both amplifier input terminals and amplifies only the voltage
difference that appears across its input terminals. Most of the amplifiers used for measuring
bioelectric signals are of the differential type. AC amplifiers have a limited frequency
response and are, therefore, used only for special medical applications such as
electrocardiograph machine.
2. Which amplifier has a limited frequency response?
a) differential amplifier
b) dc amplifiers
c) ac coupled amplifiers
d) carrier amplifiers
View Answer
Answer: b
Explanation: AC amplifiers have a limited frequency response and are, therefore, used only
for special medical applications such as electrocardiograph machine. For
electrocardiograms, an ac amplifier with sensitivity, giving 0.5 mV/cm, and a frequency
response up to 1 kHz and an input impedance of 2 to 5 MW is used. For such applications
as retinography, EEG and EMG, more sensitive ac amplifiers are required, giving a chart
sensitivity of say 50 mV/cm with a high input impedance of over 10 MW.
3. ______________ are used with transducers which require an external source of
excitation.
a) carrier amplifiers
b) dc amplifiers
c) ac coupled amplifiers
d) differential amplifier
View Answer
Answer: a
Explanation: Carrier amplifiers are used with transducers which require an external source
of excitation. They are characterized by high gain, negligible drift, extremely low noise and
the ability to operate with resistive, inductive or capacitive type transducers. They
essentially contain a carrier oscillator, a bridge balance and calibration circuit, a high gain
ac amplifier, a phase-sensitive detector and a dc output amplifier.
4. DC amplifiers are employed with _______ feedback type.
a) positive
b) negative
c) depends on the application
d) can be any positive or negative does’t matter
View Answer
Answer: b
Explanation: DC amplifiers are generally of the negative feedback type. They are used for
medium gain applications down to about 1 mV signal levels for full scale. They are not
practical for very low level applications because of dc drift and poor common-mode rejection
capabilities.
5. DC amplifiers are mostly used for very low level applications because they offer very less
dc drift and high common mode rejection capabilities.
a) True
b) False
View Answer
Answer: b
Explanation: DC amplifiers are not practical for very low level applications because of dc
drift and poor common-mode rejection capabilities. They are usually employed as pen drive
amplifiers in direct writing recorders. They are used for medium gain applications down to
about 1 mV signal levels for full scale.
6. Chopper stabilized dc amplifiers are complex amplifiers having ________ amplifiers
incorporated in the module.
a) 1
b) 2
c) 3
d) 4
View Answer
Answer: c
Explanation: Chopper stabilized dc amplifiers are used for low level but preferably wideband
applications such as oscilloscopes, tape recorders and light beam oscilloscope recorders.
These are complex amplifiers having three amplifiers incorporated in the module. This
includes an ac amplifier for signals above about 20 Hz, a dc chopper input amplifier for
signals from about 20 Hz down to dc plus wideband feedback stabilized dc amplifier.
7. Which of the following amplifier is employed with resistive transducers which require an
external source of excitation?
a) differential amplifier
b) ac coupled amplifier
c) carrier amplifier
d) dc bridge amplifier
View Answer
Answer: d
Explanation: DC bridge amplifiersare employed with resistive transducers which require an
external source of excitation. Essentially, the amplifier comprises of a stable dc excitation
source, a bridge balance and calibration unit, a high gain differential dc amplifier and a dc
output amplifier. They can be used as conventional dc high gain amplifiers and offer
operating simplicity and high frequency response.
8. Chopper input dc amplifiersare preferred for low level inputs to instrumentation systems
because of their high sensitivity, negligible drift and excellent common mode rejection
capability.
a) True
b) False
View Answer
Answer: a
Explanation: True. Chopper input dc amplifiersare preferred for low level inputs to
instrumentation systems because of their high sensitivity, negligible drift and excellent
common mode rejection capability. Their high frequency response is limited to about one
half of the input chopper frequency.

1. The frequency range of ECG is ____________

a) 0.05-150 HZ
b) 500-1500 Hz
c) 5-500 kHz
d) 0.5-150 MHz
View Answer
Answer: a
Explanation: The diagnostically useful frequency range is usually accepted as 0.05 to 150
Hz. Although the electric field generated by the heart can be best characterized by vector
quantities, it is generally convenient to directly measure only scalar quantities, i.e. a voltage
difference of mV order between the given points of the body.
2. Which of the following amplifier circulatory is employed to reduce the hum noise
generated by the power supply in the ECG circuit?
a) band pass filters
b) high pass filters
c) notch filters
d) low pass filters
View Answer
Answer: c
Explanation: A notch filter is employed to suppress the hum noise generated by the power
supply in the ECG circuit. CMRR of the order of 100–120 dB with 5 kW unbalance in the
leads is a desirable feature of ECG machines. The instability of the baseline, originating
from the changes of the contact impedance, demands the application of the automatic
baseline stabilizing circuit.
3. The branch of medicine that deals with the provision and use of artificial devices such as
splints and braces is _________
a) prosthetics
b) orthotics
c) laproscopic
d) augmentative communication
View Answer
4. The sensitivity of an electrocardiograph is typically set at 10 mm/mV.
a) True
b) False
View Answer
Answer: a
Explanation: It is true. The sensitivity of an electrocardiograph is typically set at 10 mm/mV.
For routine work, the paper recording speed is 25 mm/s. Amplitude measurements are
made vertically in millivolts. Time measurements and heart rate measurements are made
horizontally on the electrocardiogram.
5. The volume of blood within the dialyzer is known as ___________
a) secondary volume
b) quarterly volume
c) priming volume
d) residual volume
View Answer
Answer: c
Explanation: The volume of blood within the dialyzer is known as priming volume. It is
desirable that this should be minimal. Priming volume of present day dialyzers ranges from
75 to 200 ml, depending on the membrane area geometry and operating conditions.
6. The ideal membrane should possess ___________ to water.
a) low permeability to water
b) high permeability to water
c) medium permeability to water
d) high permeability to waste
View Answer
7. To achieve optimum performance and to enable the relationship of change in resistance
with the volume of the cell to hold good, it is recommended that the ratio of the aperture
length to the diameter of the aperture should be __________
a) 75:1
b) 0.75:100
c) 0.75:1
d) 0.5:10
View Answer
8. The blood is a poor conductor of electricity.
a) True
b) False
View Answer
9. In floating electrodes metal electrode does not make direct contact with the skin.
a) True
b) False
View Answer
Answer: a
Explanation: In a floating electrode, the metal electrode does not make direct contact with
the skin. The electrode consists of a light weighted metalled screen or plate held away from
the subject by a flat washer which is connected to the skin. Floating electrodes can be
recharged, i.e. the jelly in the electrodes can be replenished if desired.

3. Which of the following technique is not employed in isolation devices?

a) resistance
b) optical
c) inductance
d) capacitance
View Answer
Answer: a
2. __________ method is based on the absorption of electromagnetic radiation in the
visible, ultraviolet and infrared ranges.
a) Cardiotocography
b) Ultrasonic therapy
c) Spectrophotometry
d) Diathermy
View Answer
Answer: c
. The method based on the absorption of radiation of a substance is known as ________
a) Absorption photometry
b) Spectrophotometry
c) Absorption tocometry
d) Absorption spectrophotoscopy
View Answer
Answer: d
1. Electrodes to measure EEG are placed on ________
a) forehead
b) scalp
c) cheek
d) ears
View Answer
Answer: b
Explanation: Electrode to measure EEG are placed on the scalp. The position of each
electrode is specified using the International 10/20 system. Each electrode site is labeled
with a letter and a number.
2. According to the international 10/20 system to measure EEG, even number denotes
which side of the brain?
a) left
b) top
c) bottom
d) right
View Answer
Answer: d
Explanation: The position of each electrode is specified using the International 10/20
system. Each electrode site is labeled with a letter and a number. Even number denotes the
right side of the head.
3. Letter F in the EEG electrode placement system denotes?
a) front
b) face
c) frontal lobe
d) fast
View Answer
Answer: c
Explanation: F denotes frontal lobe of the head. The position of each electrode is specified
using the International 10/20 system. Each electrode site is labeled with a letter and a
number.
4. Normal EEG frequency range is _______
a) 50-500Hz
b) 0.5-50HZ
c) 0.05-5Hz
d) 1-200Hz
View Answer
Answer: b
Explanation: The frequency varies greatly with different behavioral states. The normal EEG
frequency content ranges from 0.5 to 50Hz. The nature of the wave varies over the different
parts of the scalp.
5. The letter T in the EEG electrode placement system denotes?
a) temporal lope
b) temper lobe
c) trace
d) timpanic
View Answer
Answer: a
Explanation: T denotes temporal lobe of the head. The position of each electrode is
specified using the International 10/20 system. Each electrode site is labeled with a letter
and a number.
6. According to the international 10/20 system to measure EEG, odd number denotes which
side of the brain?
a) left
b) right
c) top
d) front
View Answer
Answer: a
Explanation: The position of each electrode is specified using the International 10/20
system. Each electrode site is labeled with a letter and a number. Odd number denotes the
left side of the head.
7. The delta wave in EEG ranges from ___________
a) 0.5-4Hz
b) 4-8Hz
c) 8-13Hz
d) 13-22Hz
View Answer
Answer: a
Explanation: The delta wave in EEG ranges from 0.5-4Hz. The theta wave in EEG ranges
from 4-8Hz. The alpha wave in EEG ranges from 8-13Hz and beta from 13-22Hz.
8. Disturbance in the EEG pattern resulting from the external stimuli is called ________
a) provoked response
b) ckoored response
c) evoked response
d) impulse response
View Answer
Answer: c
Explanation: Disturbance in the EEG pattern resulting from the external stimuli is called
evoked response. The stimuli could be a flash light or a click of sound. The stimuli can be
repeated and the EEG waveform can be observed to find the activities occurring because of
the stimuli.
9. The peak to peak amplitude of the waves that can be picked from the scalp is
______________
a) 100mV
b) 100V
c) 100uV
d) 10mV
View Answer
Answer: c
Explanation: The EEG signal can be picked up with electrodes either from the scalp or
directly from the cerebral cortex. The peak to peak amplitude of the waves that can be
picked up from the scalp is normally 100uV. The frequency varies greatly with different
behavioral states.
10. Which rhythm is the principal component of the EEG that indicates the alertness of the
brain?
a) theta rhythm
b) gamma rhythm
c) beta rhythm
d) alpha rhythm
View Answer
Answer: d
Explanation: The alpha rhythm is the principal component of the EEG and is an indicator of
the state of alertness of the brain. It serves as an indicator of the depth of anesthesia in the
operating room. The frequency of the EEG seems to be affected by the mental activity of a
person.

1. The material used in limb surface electrode is ___________

a) German silver
b) Copper
c) Gold
d) Platinum
View Answer
Answer: a
Explanation: The most common type of electrode most routinely used for recording ECG
are rectangular or circular surface limb electrodes. The material used in them is German
silver, nickel silver or nickel plated steel. They are applied to the surface of the body with
electrode jelly.
2. Welsh cup electrodes have __________
a) low contact impedance
b) negligible contact impedance
c) high contact impedance
d) zero contact impedance
View Answer
Answer: c
Explanation: Welsh cup electrodes or suction electrodes is a metallic cup shaped electrode
which is used for recording ECG from various positions from the chest. It has a high contact
impedance as only the rim of the electrode is in contact with the skin. It is commonly used to
record the unipolar chest leads.
3. In floating electrodes metal electrode does not make direct contact with the skin.
a) True
b) False
View Answer
Answer: a
Explanation: In floating electrode the metal electrode does not make direct contact with the
skin. The electrode consists of a light weighted metalled screen or plate held away from the
subject by a flat washer which is connected to the skin. Floating electrodes can be
recharged, i.e. the jelly in the electrodes can be replenished if desired.
4. The main design feature of pregelled disposable electrodes which helps to reduce the
possibility of artefacts, drift and baseline wandering is _____________
a) low absorbency buffer layer with isotonic electrolyte
b) high absorbency buffer layer with isotonic electrolyte
c) high absorbency buffer layer without isotonic electrolyte
d) low absorbency buffer layer without isotonic electrolyte
View Answer
Answer: b
Explanation: The main design feature of pregelled disposable electrode that helps in
reducing the possibility of artefacts, drift and baseline wandering is the provision of high
absorbency buffer layers with isotonic electrolyte. This layer absorbs the effects of
movement of the electrode in relationship to the skin and attempts to maintain the
polarization associated with the half-cell potential constant.
5. Recording electrical activities associated with heart is known as ____________
a) EEG
b) EOG
c) EMG
d) ECG
View Answer
Answer: d
Explanation: The recording of the electrical activities associated with the functioning of the
heart is known as electrocardiogram. ECG is a quasi-periodical, rhythmically repeating
signals synchronized by the function of the heart, which acts as a generator of bioelectric
events. This generated signals can be described by the means of a simple electric dipole.
6. Which of the following is considered to be the primary pacemaker of the heart?
a) sino-atrial node
b) atrio-ventricular node
c) purkinje fibres
d) bundle of his
View Answer
Answer: a
Explanation: Located in the top right atrium near the entry of the vena cava, are a group of
cells known as the sino-atrial node (SA node) that initiates the heart activity. Because this is
also considered as the primary pacemaker of the heart. The SA node is 25 to 30 mm in
length and 2 to 5 mm in thickness.
7. Atrio ventricular node is located at __________
a) upper part of the heart wall between the two atrial
b) lower part of the heart wall above the two atrial
c) lower part of the heart wall between the two atrial
d) upper part of the heart wall above the two atrial
View Answer
Answer: c
Explanation: The AV node is located in the lower part of the wall between the two atria. The
AV node delays the spread of excitation for about 0.12s, due to the presence of a fibrous
barrier of non-excitable cells that effectively prevent its propagation from continuing beyond
the limits of stria.
8. Buffer amplifier converts ____________
a) low impedance signals to high impedance signals
b) high impedance signals to low impedance signals
c) ac impedance signals to dc impedance signals
d) dc impedance signals to ac impedance signals
View Answer
Answer: b
Explanation: Noise is typically generated from motion artefacts and power line interference.
A common solution used to suppress noise in dry electrode signals is a buffer amplifier. A
buffer amplifies is essentially an impedance converter, that converts high impedance
signals to low impedance signals.
9. Which of the following is a wireless ECG acquiring system?
a) pregelled disposable electrodes
b) limb electrodes
c) pasteless electrodes
d) smart pad
View Answer
Answer: d
Explanation: Smart pad is a system that displays patients electrocardiogram signals without
adhesive pads, wires or active intervention from a clinician. The system automatically
selects three electrodes from an array of Cu/Ni fabric based electrodes patterned on a thin
pad on which the patient lies. The selected electrodes are used to provide a differential 3
lead measurement of the patient’s ECG, which is then transmitted wirelessly and displayed
on a laptop computer.
10. Before placing the electrodes the skin should be __________
a) wet
b) dry
c) hairy
d) oily
View Answer
Answer: b
Explanation: The skin should be dry. Poor skin prep prompts undesirable curio and not
putting the terminals where they ought to be can change the morphology (shape) of the
waveforms the specialist will decipher. The purpose of decent skin prep is to expel soil,
dead skin cells, oils, skin cream, counterfeit tan, body powder, sweat and so forth. These
sources can prompt poor contact with the sensors and ancient rarity.
1. Which of the following instrument is used for recording the electrical activity of the brain?
a) ECG
b) EMG
c) PCG
d) EEG
View Answer
Answer: d
Explanation: Electroencephalograph is an instrument for recording the electrical activity of
the brain, by suitably placing surface electrodes on the scalp. EEG, describing the general
function of the brain activity, is the superimposed wave of neuron potentials operating in a
non-synchronized manner in the physical sense.
2. EEG electrodes are larger in size than ECG electrodes.
a) True
b) False
View Answer
Answer: b
Explanation: Several types of electrodes may be used to record EEG. These include: Peel
and Stick electrodes, Silver plated cup electrodes and Needle electrodes. EEG electrodes
are smaller in size than ECG electrodes.
3. _______ is the superimposed wave of neuron potentials operating in a non-
synchrronized manner in a physical sense.
a) VCG
b) ECG
c) EEG
d) PCG
View Answer
Answer: c
Explanation: Electroencephalograph is an instrument for recording the electrical activity of
the brain, by suitably placing surface electrodes on the scalp. EEG, describing the general
function of the brain activity, is the superimposed wave of neuron potentials operating in a
non-synchronized manner in the physical sense.
4. Which of the following is material is used to improve electrical contact?
a) Silver Tungsten
b) Electrode jelly
c) Silver Graphite
d) Copper Tungsten
View Answer
Answer: b
Explanation: Electrode jelly or paste is used to improve the electrical contact. If the
electrodes are intended to be used under the skin of the scalp, needle electrodes are used.
They offer the advantage of reducing movement artefacts.
5. Whose electrodes give high skin impedance as compared to ECG?
a) VCG
b) PCG
c) EMG
d) EEG
View Answer
Answer: d
Explanation: EEG electrodes give high skin contact impedance as compared to ECG
electrodes. Good electrode impedance should be generally below 5 kilohms. The
impedance between a pair of electrodes must also be balanced or the difference between
them should be less than 2 kilohms.
6. What are generally designed to have a very high value of input impedance to take care of
high electrode impedance?
a) Montages
b) Electrodes
c) Preamplifiers
d) Filters
View Answer
Answer: c
Explanation: Good electrode impedance should be generally below 5 kilohms. Impedance
between a pair of electrodes must also be balanced or the difference between them should
be less than 2 kilohms. EEG preamplifiers are generally designed to have a very high value
of input impedance to take care of high electrode impedance.
7. Voltage difference between an active electrode on the scalp with respect to reference
electrode at ear lobe or any other part of body is known as ___________ recording.
a) Monopolar
b) Bipolar
c) Unipolar
d) Nonpolar
View Answer
Answer: a
Explanation: EEG may be recorded by picking up the voltage difference between an active
electrode on the scalp with respect to a reference electrode on the ear lobe or any other
part of the body. This type of recording is called ‘monopolar’ recording.
8. How is bipolar recording done?
a) Omni channel EEG
b) Multi channel EEG
c) Uni Channel EEG
d) Non Channel EEG
View Answer
Answer: b
Explanation: ‘bipolar’ recording is more popular wherein the voltage difference between two
scalp electrodes is recorded. Such recordings are done with multi-channel
electroencephalographs.
9. EEG signals picked up by surface electrodes are usually small as compared to ECG.
a) True
b) False
View Answer
Answer: a
Explanation: Yes, EEG signals picked up by the surface electrodes are usually small as
compared with the ECG signals. They may be several hundred microvolts, but 50 microvolts
peak-to-peak is the most typical.
10. A pattern of electrodes on the head and the channels they are connected to are
__________
a) Amplifiers
b) Oscilloscope
c) Montage
d) Wires
View Answer
Answer: c
Explanation: A pattern of electrodes on the head and the channels they are connected to is
called a montage. Montages are always symmetrical. The reference electrode is generally
placed on a nonactive site such as the forehead or earlobe.
11. Where is the reference electrode placed?
a) nasal
b) cervical
c) forehead
d) facial
View Answer
Answer: c
Explanation: A pattern of electrodes on the head and the channels they are connected to is
called a montage. Montages are always symmetrical. The reference electrode is generally
placed on a nonactive site such as the forehead or earlobe.
12. What is the typical value of the calibration signal?
a) 10 uV/cm
b) 30 uV/cm
c) 50 uV/cm
d) 70 uV/cm
View Answer
Answer: c
Explanation: A calibrating signal is used for controlling and documenting the sensitivity of
the amplifier channels. This supplies a voltage step of adequate amplitude to the input of
the channels. A typical value of the calibration signal is 50 uV/cm.
13. Preamplifiers used in electroencephalograph have high gain and low noise
characteristics.
a) True
b) False
View Answer
Answer: a
Explanation: Yes, preamplifier used in electroencephalographs must have high gain and low
noise characteristics because the EEG potentials are small in amplitude. In addition, the
amplifier must have very high common-mode rejection to minimize stray interference
signals from power lines and other electrical equipment.
14. EEG machines have notch filter sharply tuned at _______ Hz as to eliminate mains
frequency interference.
a) 10
b) 30
c) 50
d) 70
View Answer
Answer: c
Explanation: EEG machines have a notch filter sharply tuned at 50 Hz so as to eliminate
mains frequency interference. These however have the undesirable property of ‘ringing’ i.e.
they produce a damped oscillatory response to a square wave calibration waveform or a
muscle potential. The use of notch filters should preferably be restricted to exceptional
circumstances when all other methods of eliminating interference have been found to be
ineffective.
15. What is the typical frequency range of standard EEG machines?
a) 0.025 to 0.05 Hz
b) 0.05 to 0.1 Hz
c) 0.1 to 70 Hz
d) 70 to 140 Hz
View Answer
Answer: c
Explanation: The typical frequency range of standard EEG machines is from 0.1 Hz to 70
Hz, though newer machines allow the detection and filtering of frequencies up to several
hundred Hertz. This may be of importance in some intracranial recordings.
5. ______ is a blood pressure measuring instrument.
a) Sphygmomanometer
b) Ergometer
c) Treadmill
d) Holtemanometer
View Answer
Answer: a
Explanation: Sphygmomanometer, an instrument for measuring blood pressure, typically
consisting of an inflatable rubber cuff which is applied to the arm and connected to a column
of mercury next to a graduated scale, enabling the determination of systolic and diastolic
blood pressure by increasing and gradually releasing the pressure in the cuff.
4. Which of the following method uses only the human eye as a measuring instrument?
a) Telemetric
b) Colorimetric
c) Polarimetric
d) Calorimetric
View Answer
Answer: b
Explanation: A colorimetric method in its simplest form uses only the human eye as a
measuring instrument. This involves the comparison by visual means of the colour of an
unknown solution, with the colour produced by a single standard or a series of standards.
The comparison is made by obtaining a match between the colour of the unknown and that
of a particular standard by comparison with a series of standards prepared in a similar
manner, as the unknown.
5. Which of the following instrument isolates monochromatic radiation in a more efficient
and versatile manner than colour filters in filter photometers?
a) Calorimeter
b) Colorimeter
c) Spectrophotometer
d) Polarimeter
View Answer
Answer: c
Explanation: A spectrophotometer is an instrument which isolates monochromatic radiation
in a more efficient and versatile manner than colour filters used in filter photometers. In
these instruments, light from the source is made into a parallel beam and passed to a prism
or diffraction grating, where light of different wavelengths is dispersed at different angles.
6. Which of the following detector is required in spectrophotometer?
a) Phototransistor
b) Photodiode
c) LDR
d) Photomultiplier
View Answer
Answer: d
Explanation: The amount of light reaching the detector of a spectrophotometer is generally
much smaller than that available for a colorimeter, because of the small spectral bandwidth.
Therefore, a more sensitive detector is required. A photomultiplier or vacuum photocell is
generally employed.
7. Spectrophotometer generally employs a 6V Xenon Arc Lamp, which emits radiation in a
wavelength region of visible light.
a) True
b) False
View Answer
8. The recorder used with spectrophotometers has _____ wavelength scanning speeds.
a) one
b) two
c) three
d) four
View Answer
9. The recorder used in spectrophotometers has ______ chart speeds.
a) three
b) five
c) seven
d) nine
View Answer
Answer: c
Explanation: The recorder used with spectrophotometers have four wavelength scanning
speeds (100, 50, 20 and 5 nm/mm) and seven chart speeds (10, 5, 2, 1, 0.5, 0.2 and 0.1
inch/mm). It has a sensitivity of 100 mV absorbance units or 100 mV/100% T.
10. Which component is used in spectrophotometer for control, Signal Processing, and
Communication functions?
a) Detector
b) Microprocessor
c) Deuterium Lamp
d) Tungsten Lamp
View Answer
Answer: b
Explanation: A microprocessor, in a spectrophotometer, could be used for the following
functions: Control functions: Wavelength scanning, automatic light source selection, control
of slit width, detector sensitivity, etc. Signal processing functions: Baseline correction, signal
smoothing, calculation of % T, absorbance and concentration, derivative, etc.
Communication functions: Keyboard entry, menu-driven operations, data presentation,
warning display, communication with external systems, etc.
2. Ag-AgCl electrodes are ___________
a) polarized
b) non-polarized
c) partially polarized
d) cannot be said
View Answer
Answer: b
Explanation: The most important and desirable property of the electrodes designed to pick
up signals from biological objects is that they should not polarize. This means that the
electrodes potential must not vary considerably even when current passes through it.
Electrodes made of Ag-AgCl yield acceptable standards of performance.
3. Silver -Silver Chloride electrodes are prepared by the process of ____________
a) centrifugation
b) etching
c) manually
d) electrolysis
View Answer
Answer: d
Explanation: Silver-Silver Chloride electrodes are normally prepared by electrolysis. Two
silver discs are suspended in a saline solution. The positive pole of dc supply is connected
to the disc to be chloride and the negative pole goes to the other disc.
4. Electrocardiography was invented by ___________
a) Willem Einthoven
b) Robert Koch
c) Werner Forssmann
d) Gertrude B.Elion
View Answer
Answer: a
Explanation: Willem Einthoven a Dutch physician and physiologist. He invented the first
Electrocardiogram (ECG or ECG) in 1903. He received the Nobel Prize for Medicine in 1924
for it.