The angle of incidence for an equilateral prism of refractive index so that the ray is parallel to the base inside the prism is
30°
20°
60°
45°
If the intensity ratio of two coherent sources used in Young's double slit experiment is 49 : 1, then the ratio between the maximum and minimum intensities in the interference pattern is
1 : 9
9 : 16
16 : 9
16 : 25
According to Rayleigh scattering law, the amount of scattering is
directly proportional to wavelength of light
directly proportional to square of wavelength of light
inversely proportional to fourth power of wavelength of light
inversely proportional to wavelength of light
The de-Broglie wavelength and kinetic energy of a particle is 2000 and 1 eV respectively. If its kinetic energy becomes 1 MeV, then its de-Broglie wavelength is
The work functions of two metals are 2.75 eV respectively. If these are irradiated by photons of energy 3 eV, the ratio of maximum momenta of the photoelectrons emitted respectively by them is
1 : 2
1 : 3
1 : 4
2 : 1
A radioactive material of half-life time of 69.3 days kept in a container. of the substance remains undecayed after (given, )
20 days
25 days
35 days
40 days
D.
40 days
Given, t1/2 = 69 − 3 days and N =
and we know,
The maximum kinetic energy of photoelectrons
depends on collector plate
is independent of emitter plate material
is independent of frequency of incident radiation
depends on the frequency of light source and the nature of emitter plate material
Identify the mismatched pair from the following
Zener diode : Voltage regulator
Germanium doped with phosphorus : n-type semiconductor
semiconductor : band gap > 3 eV
p-n junction diode : rectifier
In a common-emitter configuration, a transistor has β = 50 and input resistance 1 kΩ. If the peak value of AC input is 0.01 V, then the peak value of collector current is
0.01 µA
500 µA
100 µA
0.5 µA
The waveforms A and B given below are given as input to a NAND gate. Then, its logic output y is
for t1 to t2 ; y = 0
for t2 to t3 ; y = 1
for t3 to t4 ; y = 1
for t4 to t5 ; y = 0