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

The dimensions of Plank's constant is same as that of.

• Energy A
• Power B
• Acceleration C
• Angular momentum 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

Compton's effect is associated with

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

Which one of the following paved the way for modern physics

• Newtonian mechanics A
• Theory of relativity B
• Quantum theory C
• All of above D

All motions are

• Absolute A
• Uniform B
• Relative C
• Variable D

The unit of work function is

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

If the energy of photon is 10 eV and work function is 5 eV, then the a value of stopping potential will be

• 50 V A
• 2 V B
• 5 V C
• 15 V D

The photoelectric effect predicts that light is made of

• Photons A
• Neutrons B
• Protons C
• None of these D

When platinum is heated is become dull red at:

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

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

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

When platinum wire is heated, it changes to cherry red at temperature.

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

The number of electrons emitted depends upon

• Colour of target surface A
• Shape of surface B
• Frequency of incident light C
• Intensity of incident light D

De-Broglie waves are associated with

• Moving charged particles only A
• Moving neutral particles only B
• All moving particles C
• All parties whether in motion or at rest D

Max planck received noble prize in:

• 1927 A
• 1932 B
• 1918 C
• 1914 D

Unit of Stephen's constant is

• W m K^-2 A
• W m^-2 K^-4 B
• W m K^-4 C
• None D

In an nihilation emitted photons moves in opposite directions to conserve.

• Mass A
• Charge B
• Energy C
• Momentum D