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WorksheetsMOD 1 2 3 4
Total questions: 15
Worksheet time: 5mins
According to the De-Broglie equation, the wavelength associated with a particle accelerated through a potential V is proportional to:
√V
1/√V
1/V
V²
In the case of natural broadening of spectral lines, the finite line width arises mainly due to:
Doppler shift
Finite lifetime of excited states
Instrumental defects
Multiple scattering
The time-independent Schrödinger equation represents variation of wave function with:
Time only
Position only
Time and position
Time and position
Confining an electron very close to the nucleus implies:
Zero kinetic energy
Very high kinetic energy
Negative potential energy
Infinite wavelength
A superconductor below the critical temperature exhibits magnetic susceptibility approximately:
+1
0
–1
–0.5
The expulsion of magnetic flux when cooling below TcT_cTc is known as:
Silsbee effect
Josephson effect
Meissner effect
Hall effect
According to Matthiessen’s rule, total resistivity of metals is:
Product of phonon and impurity resistivity
Sum of phonon and impurity resistivity
Difference between phonon and impurity resistivity
Independent of temperature
Density of states g(E)represents:
Number of photons emitted
Number of available energy levels between E and E+dE per unit volume
Number of charge carriers per atom
Difference between conduction and valence bands
Stimulated emission produces photons that:
Are incoherent and random
Have same phase, energy and direction as incident photon
Have lower energy than incident photon
Travel backwards
A metastable state is characterized by:
Very short lifetime (10⁻⁸ s)
Very long lifetime (10⁻³ to 10⁻² s)
No lifetime
Oscillatory lifetime
Energy gap relation in superconductors is:
kTc
3.6kTc
0.36kTc
36kTc
The entropy of a superconductor compared to normal state is:
Higher
Lower
Equal
Depends on magnetic field
Which material cannot be a superconductor?
Lead
Mercury
Copper
Tin
Which process is responsible for laser action?
Induced absorption
Spontaneous emission
Stimulated emission
Nuclear fission
Metastable states are essential because they:
Have extremely short lifetime
Allow atoms to stay longer to build population
Stop stimulated emission
Reduce energy gap
