Superconductivity
In superconductivity the conductivity of a material becomes
a. Zero
b. Finite
c. Infinite
d. None of the above
(Ans:c)
In superconductivity, the electrical resistance of material becomes
a. Zero
b. Infinite
c. Finite
d. All of the above
(Ans:a)
The temperature at which conductivity of a material becomes infinite is called
a. Critical temperature
b. Absolute temperature
c. Mean temperature
d. Crystallization temperature
(Ans:a)
In superconductors, the Fermi energy level is
a. Below the ground state
b. Midway between the ground state and first excited state
c. Above first excited state
d. At first excited state
(Ans:b)
The superconducting state is perfectly _____ in nature.
a. Diamagnetic
b. Paramagnetic
c. Ferromagnetic
d. Ferromagnetic
(Ans:a)
Which of the following are the properties of superconductors?
a. They are diamagnetic in nature
b. They have zero resistivity
c. They have infinite conductivity
d. All of the above
(Ans:d)
The minimum amount of current passed through the body of superconductor
in order to destroy the superconductivity is called
a. Induced current
b. Critical current
c. Eddy current
d. Hall current
(Ans:b)
The energy required to break a cooper pair is ___ of the energy gap of
superconductor.
a. One half
b. Equal to
c. Twice
d. Thrice
(Ans:b)
The copper pair has
i. Equal and opposite momenta
ii. Equal and opposite spin
iii. Unequal and same spin
Which of the above are true?
a. Only i
b. Only ii
c. i & ii
d. i & iii
The binding energy for a cooper pair is
a. 10^-2 eV
b. 10^-4 eV
c. 10^-6 eV
d. 10^-8 eV
(Ans:b)
There are three important lengths which enter the theory of
superconductivity except
a. London penetration length
b. Intrinsic coherence length
c. Normal electron mean free length
d. Mean path length
(Ans:d)
The magnetic lines of force cannot penetrate the body of a superconductor, a
phenomenon is known as
a. Isotopic effect
b. BCS theory
c. Meissner effect
d. London theory
(Ans:c)
Which of the following conductor has highest critical temperature?
a. Aluminium
b. Zinc
c. Molybdenium
d. Tin
(Ans:d)
The critical magnetic field is that at which
(a) A material behaves like a normal conductor for the last time
(b) A material maintains its superconductivity for the last time
(c) A material has its mixed normal-superconducting state
(d) A material transforms from a superconducting state to an Insulating state
Answer:
Option (b)
The critical temperature is that temperature where
(a) the resistivity of a superconducting metal drops to zero
(b) the current flowing through a superconductor is minimum
(c) the magnetic field inside a superconductor becomes constant
(d) none of these
Answer:
Option (a)
Meissner effect is shown by the equation
(a) B=0 at T>Tc
(b) B=0 at T≤Tc
(c) B≠0 at T≥Tc
(d) div B=0 at T=Tc
Answer:
Option (b)
Meissner effect is strictly followed by
(a) diamagnetic material
(b) ferromagnetic material
(c) superconducting material
(d) paramagnetic material
Answer:
Option (a)
The cooper pair is
(a) two electrons moving in the same direction
(b) two electrons with resultant spin-zero
(c) two electrons connected like a boson
(d) two electrons connected through a phonon
Answer:
Option (d)
If the material is transformed into a superconducting state from a normal state, its ent
(a) decreases
(b) increases
(c) remains same
(d) shows abrupt change
Answer:
Option (a)
In superconductivity the conductivity of a material becomes
i. Zero
ii. Finite
iii. Infinite
iv. None of the above
In superconductivity, the electrical resistance of material becomes
i. Zero
ii. Infinite
iii. Finite
iv. All of the above
The temperature at which conductivity of a material becomes infinite is called
i. Critical temperature
ii. Absolute temperature
iii. Mean temperature
iv. Crystallization temperature
The superconducting state is perfectly _____ in nature.
i. Diamagnetic
ii. Paramagnetic
iii. Ferromagnetic
iv. Ferromagnetic
The magnetic lines of force cannot penetrate the body of a superconductor, a
phenomenon is known as i. Isotopic effect
ii. BCS theory
iii. Meissner effect
v. London theory
At the critical temperature, the resistance of a super conductor
i. decrease rapidly
ii. Increase rapidly
iii. Remains constant
iv. Increase slowly
