Superconductors

Combination of electron and positive site in BCS theory is called …………...

• Phonon

• Positron

• Neutron

• Electron

In the BCS theory ……………… charged lattice is considered

• Positive charged

• Negative charged

• Neutral

• None of these

Identify the correct condition in which the absorption of infrared radiation occurs in Superconductors?

• hω ≤ 2Δ0

• hω ≥ 2Δ0

• hω = 2Δ0

Once the absorption of IR radiation happens in Superconductors,the energy gap could be determined by,

• wavelength of IR

• Frequency of IR

• Speed of IR

• Energy of IR

In Josephson effect, the static potential results in alternating current

• true

• false

Choose the correct answer(s)

Josephson frequency includes the ratio of ____________

• Charge of the electron to the planck constant

• Two times the charge of the electrons to the Planck constant

• Two times the Planck constant to the charge of the electron.

• Charge of the cooper pair to the planck constant.

In type two superconductors, the surface energy will be negative when,

( here ξ is the coherence length ,λ is the penetration depth)

• ξ< λ

• λ< ξ

• ξ ≥λ

• λ>ξ

Coherence length ξ is

1. ξ ∝ ℋc

2. ξ ∝ Tc

3. ξ ∝ 1/Tc

4. ξ ∝ 1/ℋc

• Both 3 and 4

• Both 1 and 3

• Both 2 and 1

• Only 2

Far from the Fermi energy, Density of of states for the superconductor is ___________ the normal metal and ___________ near the Fermi energy.

• Same, same

• Changes greatly, same

• Same, changes greatly

• Changes greatly, changes greatly

Find the concept?

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