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

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

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

Platinum wire becomes white at a temperature of.

• 1600^oC A
• 1300^oC B
• 1100^oC C
• 900^oC D

Einstein photoelectric equation is

• 
  A
• 
  B
• 
  C
• None of these D

The unit for Plank's constant is:

• Js^-1 A
• Jm B
• Js  C
• Jm² D

Potassium Cathodes in photocell emit electrons for a light.

• Visible A
• Infra red B
• Ultra violet C
• X rays D

When platinum is heated is become dull red at:

• 900°C A
• 500°C B
• 800°C C
• 1100°C D

Platinum wire becomes yellow at a temperature of.

• 900 ^oC A
• 1300^oC B
• 1600^oC C
• 500^oC D

An electron miroscope emplys which to one of the following particles?

• Electron ahve a wave nature A
• Electrons can be focused by an electric field B
• Electrons can be focused by a magnetic field C
• All of the above D

The existence of positron was discovered in:

• 1929 A
• 1928 B
• 1931 C
• 1933 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

When platinum is it becomes orange at

• 500^oC A
• 900^oC B
• 1100^oC C
• 1300^oC 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

When the K.E. of photoelectric is zero, the frequency of incident photon is.

• Less than A
• greater than B
• Equal to C
• Much greater D

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

The mass of an object will be doubled at speed.

• 2.6 x 10⁸ m/s A
• 1.6 x 10⁸ m/s B
• 2.6 x 10⁷ m/s C
• 3.6 x 10⁷ m/s D

Einstein was awarded Nobel prize in physics in

• 1905 A
• 1911 B
• 1918 C
• 1921 D

Compton shift is maximum for scattering angle of photon

• 0^o A
• 90^o B
• 180^o C
• 45^o D