Second Year Physics Chapter 19 Online MCQ Test for 2nd Year Physics Chapter 19 Dawn of Modern Physics Preparation

The minimum frequency needed to emit an electron form metal surface is called:

• Work function A
• Threshold frequency B
• Quanta frequency C
• All of above D

The existence of positron was discovered in:

• 1929 A
• 1928 B
• 1931 C
• 1933 D

Minimum energy needed to escape an electron  ofrm metal surface is called:

• Threshold energy A
• Threshold frequency B
• Work function C
• Work ability D

Photo electrons are emitted y using visible light when the metal is.

• sodium A
• Copper B
• Nicked C
• Cobalt D

The physical quantity related to photon, that does not change in Compton scattering is.

• Energy A
• Speed B
• Frequency C
• Wavelength D

Earth orbital speed is.

• 10 km/s A
• 20 km/s B
• 30 km/s C
• 40 km/s D

Using relativistic effects the location of an air craft after an hour fight can be predicated about

• 20 m A
• 50 m B
• 760 m C
• 780 m D

Albert Einstein got noble prize for service in:

• Pair production A
• Annihilation of matter theory B
• Compton effect C
• Photoelectric effect D

Pair production cannto take place in vacuum because :

• Mass in not conserved A
• Momentum is not conserved B
• Energy is not conserved C
• Charge is not conserved D

• Wien's constant A
• Planck's constant B
• Davison constant C
• Lumber's constant D

The numerical value of Compton wavelength is equal to

• 3.43 x 10^-12 m A
• 1.43 x 10^-12m B
• 2.43 x 10^-12m C
• 0.43 x 10^-12m D

unit of Plank's constant is same as that of.

• Acceleration A
• Angular momentum B
• Linear momentum C
• Entropy D

The wavelength associated with the protons moving at speed of 40 m/s is.

• 7.20 nm A
• 9.02 B
• 15.7 nm C
• 17.3 nm D

Compton's effect is associated with

• gamma rays A
• Beta rays B
• X rays C
• Positive rays D

Number of electros emitted in photo electric effect depend upon.

• Intensity of incident light A
• Frequency of incident light B
• Energy of incident light C
• Wavelength of incident of light D

Anti particle of electron is

• Proton A
• Photon B
• Neutron C
• Positron D

Antiparticle of electron is.

• proton A
• Photon B
• Positron C
• Neutron D