Super Conductors Flashcards
The phenomena of super conductors was first discovered by ___________
a) Kammerlingh Onnes
b) Neils bohr
c) Richard Smalley
d) Otto lehman
Kammerlingh Onnes
Richard Smalley discovered the fullerene by laser ablation method.
Super conductors are discovered in the year _______
a) 1900
b) 1991
c) 1911
d) 1905
1911
Super conductors are discovered in the year 1911 by Kammerlingh Onnes. He is a Dutch physicist. When he was measuring the resistivity of the mercury below 4.2K he found the super conductors.
The earliest superconductors to be studied elaborately is ________
a) Niobium alloy
b) Copper alloys
c) Steel alloys
d) Iron alloy
Niobium alloy
The shifting of electrons in super conductors is prevented by _________
a) Quantum effect
b) Threshold energy level
c) Energy barrier
d) Orbitals
Quantum effect
The normal metal passes into super conducting state at ___________
a) High temperature
b) Low temperature
c) Critical temperature
d) No temperature
Critical temperature
Based on magnetic response super conductors are of __________ types.
a) 1
b) 2
c) 3
d) 4
b) 2
Type 1 - ideal (Soft) super conductors
Type 2 - hard super conductors.
Ideal super conductors completely become __________ at super conducting state.
a) Diamagnetic
b) Ferro magnetic
c) Ferri magnetic
d) Para magnetic
Diamagnetic
The ideal super conductors exhibit __________
a) Meissner effect
b) Mesmeric effect
c) Mesomeric effect
d) Monomeric effect
Meissner effect
The expulsion of magnetic flux from the interior of a piece of super conducting material as the material undergoes transition to super conducting phase.
The hard super conductors are those in which the ideal behaviour is seen up to a ________ critical magnetic field.
a) Higher
b) Lower
c) Moderate
d) Zero
Lower
The hard super conductors are those in which the ideal behaviour is seen up to a lower critical magnetic field beyond which the magnetization gradually changes and attains zero.
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
Midway between the ground state and first excited state
The superconducting state is perfectly _____ in nature.
Diamagnetic
Paramagnetic
Ferromagnetic
Ferromagnetic
Diamagnetic
magnetic susceptibility = -1
Which of the following are the properties of superconductors?
They are diamagnetic in nature
They have zero resistivity
They have infinite conductivity
All of the above
All of the above
The minimum amount of current passed through the body of superconductor in order to destroy the superconductivity is called
Induced current
Critical current
Eddy current
Hall current
Critical current
The energy required to break a cooper pair is ___ of the energy gap of superconductor.
One half
Equal to
Twice
Thrice
Equal to
The binding energy for a cooper pair is
10^-2 eV
10^-4 eV
10^-6 eV
10^-8 eV
10^-4 eV
The magnetic lines of force cannot penetrate the body of a superconductor, a phenomenon is known as
Isotopic effect
BCS theory
Meissner effect
London theory
Meissner effect
Which of the following conductor has highest critical temperature?
Aluminium
Zinc
Molybdenium
Tin
Tin
The magnetization ‘M’ of a superconductor in a filed H is
(a) extremely small
(b) -H
(c) -1
(d) Zero
(b) -H
in superconductors, B=0
μ(H+M)=0
If a small amount of Cu is added to a Ni conductor then the
(a) the resistivity of Ni will increase at all temperatures because Cu is a better conductor than Ni
(b) residual resistivity of Ni at low temperatures will increase as Cu atoms act as defect centers
(c) the resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects
(d) the resistivity of Ni remains unaltered as Cu atoms give the same number of free electrons as Ni atoms
the resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects
Which one of the following is the best definition of a superconductor?
(a) it is a material showing perfect conductivity and the Meissner effect below a critical temperature
(b) It is a conductor having zero resistance
(c) It is a perfect conductor with the highest diamagnetic susceptibility
(d) It is a perfect conductor but becomes resistive when the current density through it exceeds a critical value
it is a material showing perfect conductivity and the Meissner effect below a critical temperature
The correct sequence of the following materials in the increasing order of magnetic susceptibility is
(a) Diamagnetic – Ferromagnetic – Paramagnetic – Superconductor
(b) Ferromagnetic – Paramagnetic – Diamagnetic – Superconductor
(c) Paramagnetic – Diamagnetic – Superconductor – Ferromagnetic
(d) Superconductor – Diamagnetic – Paramagnetic – Ferromagnetic
Superconductor – Diamagnetic – Paramganetic – Ferromagnetic
Superconductors are becoming popular of their use in
(a) generating a very strong magnetic field
(b) manufacture of bubble memories
(c) generating electrostatic field
(d) generating regions free from the magnetic field
generating a very strong magnetic field
The dc resistivity and permeability exhibited by a type-I superconductor are respectively
(a) Zero and Zero
(b) Zero and unity
(c) Unity and Zero
(d) Unity and Unity
Zero and Zero
