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

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

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

Platinum wire becomes yellow at a temperature of.

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

The concept of direction is purely

• Relative A
• Absolute B
• Relative to the motion C
• None of these D

Antiparticle of electron is.

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

Compton shift is maximum for scattering angle of photon

• 0^o A
• 90^o B
• 180^o C
• 45^o D

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

In 1905, the special theory of relativity was proposed by

• Einstein A
• Bohr B
• Maxwell C
• De Broglie 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

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 converses of annihilation of matter is:

• Photoelectric effect A
• Relativistic effect B
• Pair production C
• Compton effect D

We can never accurately describes all aspects of sbatomic particles simulatanously. It is correct according to:

• Uncertainity Priciple A
• De-broglie Theory B
• Einstin Theory C
• Photo electric effect D

Light of 4.5 eV is incident on a Cesium surface and stopping potential is 0.25 eV, maximum K.E. of emitted electron is.

• 4.5 eV A
• 4.25 eV B
• 4.75 eV C
• 0.25 eV 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

Earth orbital speed is.

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

The energy of the photon of wavelength 500 nm is.

• 3.10 eV A
• 2.49 eV B
• 1.77 eV C
• 1.52 eV 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