a) The resistance of two wires is 25 Ω when connected in series and 6Ω
when joined in parallel. Calculate the resistance of each wire.
b) A 100ohm resistor is connected across the terminals of 2.5 V battery.
What is the power dissipation in the resistor?
c) Calculate the Thevenin resistance across the terminal AB for the following
circuit.
Fig.1
d) Classify the electrical energy sources?
e) The resistance of a 200W, 250V lamp is__________
f) A capacitor of capacitance 500µF is in series with a resistor of 100Ω. Find
Z, if the supply frequency is 60Hz
g) Draw the impedance triangle of RL series load and represent its
impedance in complex notation.
h) Define the terms time period and frequency of single-phase alternating
quantity
i) A sine wave has a frequency of 50 Hz. Its angular frequency is _______.
j) Form factor is the ratio of _________
Determine the current delivered by the source in the circuit shown in Fig.1
below.
Fig.2
Write the mesh current equations in the circuit shown in Fig.2. below and
determine the currents.
Fig.3
State and explain Thevenin’s Theorem with an example?
Derive average and RMS Values of a full rectified sinusoidal voltage waveform?
Analyze the behavior of a series RC circuit when it is connected to the AC
supply with equations and wave forms?
A series RL circuit R=8 ohm, L=3.5 Henry. If the supply voltage is 220V and
frequency is 60 Hz, Find:
i. Impedance of the circuit
ii. Current
iii. Drop across each circuit element
a) State Thevenin’s Theorem
b) Determine the value of I1 in the network below.
Fig.1
c) Sixteen resistances each of 32Ω are connected in parallel. What is the
equivalent resistance of this combination?
d) Calculate the effective resistance of the following combination of
resistances.
Fig.2
e) What are active elements and passive elements? Can passive elements
generate power?
f) A choke coil takes a current of 2A lagging 600 behind the applied voltage
of 200V at 50Hz. Calculate the impedance of the coil when it is connected
to 100V, 25Hz supply.
g) Define the terms:
i. Phase
ii. Phase difference with reference to ac circuits
h) Draw the phasor diagram of voltage and current for pure L and pure C
networks.
i) Define peak factor and form factor?
j) The RMS value of an AC sinusoidal voltage is 230 V, what is it’s maximum
value?
State and explain KCL and KVL with an example.
Find the Mesh Currents I1,I2 and I3
Fig.3
State and explain Superposition Theorem with an example.
Derive average and RMS Values of a half rectified sinusoidal voltage
waveform?
Analyze the behavior of a capacitor when it is connected to the AC supply with
equations and wave forms?
A series R-C circuit has a resistance of 50 ohm in Series with a capacitance of
100µF and is connected across 230 V, 50Hz supply. Calculate:
i. Impedance of the circuit
ii. The circuit current
a) Find the supply current to the circuit shown in Fig.1.
Fig.1
b) State Superposition theorem.
c) Two voltmeters A and B, having resistances of 5.2kΩ and15kΩ
respectively are connected in series across 240V supply. What is the
reading on each voltmeter?
Fig.2
d) List the limitations of Ohm’s Law.
e) A resistance R is connected in series with 20 Ω and 48 Ω. If the total
measured resistance is 100 Ω, calculate value of resistance R.
f) Draw the phasor diagram of voltage and current for pure R and pure C
networks.
g) Define the terms associated with sinusoidal function:
i. Time period
ii. Frequency
h) Define R.M.S. value and Average value.
i) Define Reactance
j) In a given series RLC circuit R is 25 Ω, Xc is 150 Ω and XL is 80 Ω. What is
the total reactance?
State and illustrate Norton’s theorem with an example?
Find the current through each resistor of the circuit shown in the Fig.1 using
nodal analysis.
Fig.3
Find the power dissipated in the 80Ω resistor using mesh analysis.
Fig.4
Derive the expression for RMS & Average value of sinusoidal current wave
form given by the equation i= Im sinwt
Show that the current in pure inductive circuit lags the voltage by 900. Draw
the wave forms for voltage and current.
A resistance of 20Ω, an inductance of 0.2H, and a capacitance of 100μF are
connected in series across 230V, 50Hz mains. Determine:
i. Impedance
ii. Current
iii. Voltage across R, L and C
