Question54:-The relation between the Einstein coefficients *A_(21)° and ‘B_(21)° is
A:-(A_(21))(B_(21))° = 1

8:-`(ಓ_(21))/(8_(21)) = ` (1)/(2)
൦. (^ (21))/(8 (21))` = ` (8011५^(2))/(८^(2))
0:-` (ಸಿ_(21))/(8_(21))` ಎ *(8pihv*(3))/(c*(3))°

Correct Answer:- Option-D
Question55:-In a canonical ensemble, the elements differ in their
A:-volume
B:-energy
C:-temperature
D:-number of particles
Correct Answer:- Option-B
Question56:-The Halmholtz free energy F, absolute temperature T and partition function Z of a canonical ensemble are
related as
AF =-kTInZ
kT InzZ
0 (72
D:-F = kTZ
Correct Answer:- Option-A
Question57:-The mass defect per nucleon is called
A:-packing fraction
B:-quadrupole moment
C:-angular momentum
D:-binding energy
Correct Answer:- Option-A
Question58:-In how many directions, the electrons in a quantum dot are confined ?
‏ا‎
‎8:-2
‎C:-3
‎D:-4
‎Correct Answer:- Option-C
Question59:-The energy versus wave vector graph of an electron in free space is a
A:-Straight line
B:-parabola
C:-hyperbola
D:-circle
Correct Answer:- Option-B
Question60:-The bandgap energy of GaAs is about
A:-0.42 eV
B:-1.42 eV
C:-0.42 keV
D:-1.42 keV
Correct Answer:- Option-B
Question61:-The light emission mechanism in LED is
A:-electroluminescence
B:-photoluminescence
C:-chemiluminescence
D:-thermoluminescence
Correct Answer:- Option-A
Question62:-In a first order phase transition, which among the following statements is true ?
A:-volume is continuous at the boundary
B:-entropy is continuous at the boundary
C:-entropy is discontinuous at the boudnary
D:-a latent heat is not involved
Correct Answer:- Option-C
Question63:-The chemical potential of a photon gas is
A:-infinity
B:-finite
C:-imaginary