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

If the kinetic energy of a free electron doubles, its de Broglie wavelength changes by the factor.

• √2 A
• 1/√2 B
• 2 C
• 1/2 D

Energy of Black body radiation depends upon

• Nature of surface of body A
• Nature of material of body B
• Shape and size of body C
• Temperature of the body D

The principle regarding the dual nature of light was first discovered by

• Heisenberg A
• Compton B
• J.J.Thomson C
• De-Broglie D

The unit of work function is

• Electron volt A
• Ampere B
• Volt cell C
• Hz D

Pair production can take place only when energy of radiation is equal and greater than 1.02 MeV, thus correct option is.

• X rays A
• Gama rays B
• Heat Radiation C
• Ultraviolet rays D

In Compton scatting, the value of shift is equal to Compton's wavelength, when X-rays is scattered at the angle of.

• 90^oC A
• Zero B
• 120^oC C
• 45^oC D

The emission of electrons from metal surface when exposed to light is called:

• Compton effect A
• Pair production B
• Photoelectric effect C
• None of above D

Internal frame is a frame is which

• 1st law holds A
• 2nd law holds B
• 3rd law holds C
• Kelvin's law holds 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

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

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

Which one of the following physical quantities change with relativistic speed?

• Length A
• Time B
• Mass C
• All of above D

The maximum kinetic energy of emitted photo electrons depends upon.

• The intensity of incident light A
• Frequency of the incident light B
• Metal surface C
• Both frequency of incident light and metal surface. D

Joule second is the unit of.

• Energy A
• Wein's constant B
• Planck's constant C
• Boyle's law D

The minimum energy required for occurrence of pair production is:

• 1.022eV A
• 1.02keV B
• 1.02Me.V C
• 1.04MeV D

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

1 kg mass will be equivalent to energy.

• 9 x 10⁸ J A
• 9 X 10¹² J B
• 9 X 10¹⁶ J C
• 9 X 10¹⁹ J D

The quantity/factor h/m_oc has the dimensions of.

• Length A
• Time B
• Mass C
• Energy D