Modern Physics

According to special theory of relativity, mass of an object moving relative to an observer with a velocity comparable to the velocity of light.

• Increases

• Decreases

• Remain constant

• None of the above

Time interval between two events as recorder by an observer in relative motion with velocity comparable to velocity of light with respect to the point of occurrence of the event.

• Dilated

• Shortens

• Remains constant

• None of the above

The S.I unit of plank’s constant is

• Joule per sec

• Joule per sec²

• Joule – sec

• Joule per sec³

When light of suitable frequency falls on the surface of a metal electrons are emitted from it, this phenomenon is known as

• Compton effect

• Thermionic emission

• Photo multiplier effect

• Photoelectric effect

Maximum kinetic energy with which electrons are emitted is directly proportional to the

• Frequency of incident light

• Intensity of incident light above the threshold value

• Wave length of incident light above the threshold wave length

• Speed of incident light

In Compton effect frequency of scattered photon is

• Less than the frequency of incident photon

• Greater than the frequency of incident photon

• Equal to the frequency of incident photon

• None of the above

According to De Broglie, the momentum of a particle in terms of wave length associated with it is given by

• $P=h\ ⁄\ λ$

• $p=hλ$

• $p=λ\ ⁄\ h$

• $p=hc\ ⁄\ λ$

Compton effect is associated with

• α -rays

• 𝛽-rays

• X-rays

• Positive rays

A photon of frequency v is incident on a metal surface whose threshold frequency is v₀. The maximum kinetic energy of the emitted electron will be

• $h(v–v_o)$

• $h(v+v_o)$

• $1/2h(v–v_o)$

• $1/2h(v+v_o)$

When X-rays are scattered by electrons their wavelength increase. This phenomenon is called

• Compton effect

• Thomson effect

• Hall effect

• None of the above