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

When platinum is it becomes orange at.

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

Pair production occurs only when energy of photon is at least equal in:

• 1.02keV A
• 1.02 eV B
• 1.02 MeV C
• 1.02 GeV D

The energy of photon is givne by

• mv2/2 A
• hf B
• Va e C
• mac¹ D

All motions are

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

The photoelectric effect predicts that light is made of

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

If an object moves with speed of light, its mass will be.

• Zero A
• Maximum B
• Minimum C
• infinity 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

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

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

Disintegration of photon on striking a nucleus into an electron and positron is known as.

• Annihilation of matter A
• Compton effect B
• Pair production C
• Photo electric effect D

Compton effect proves.

• Wave nature of radiation A
• Wave nature of particle B
• Dual nature of particle C
• Particle nature of radiations 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

Compton's effect is associated with

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

Earth orbital speed is.

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

The special theory of relativity based on.

• One postulate A
• Two postulates B
• Three postulates C
• Four postulates D