Photon

Question 1

Photoelectric effect

Answer 1

emission of a electron when a ray of light falls into the metal surface.

Question 2

Threshold frequency

Answer 2

the minimum frequency of incident radiation required to eject the electron from the metal surface. Doesnot depend on the intensity of a light.Denoted by fnod

Question 2

Photoelectric emission

Answer 2

The process of ejection of electron from its metal surface.

Question 3

Photoelectric equation normal,in terms of stooping potential and work function.

Answer 3

E=hf
hf=hfnod+eVnod
In terms of stooping potential
hf=hfnod- (φ)

Question 3

Stooping potential

Answer 3

minimum retarding potential applied at anode at which the photoelectric current becomes zero.Denoted by Vnod.

Question 4

Work function

Answer 4

minimum energy required to eject a electron from a metal surface without imparting any KE onto it.

Question 5

Does K.E or fnod (threshold frequency) depend on the intensity of light?

Answer 5

No because these both terms depend upon the frequency of light rather than intensity of light.

Question 6

In which reason does the Photoelectric current is greater infrared or ultraviolet? why does in uv region it can cause severe burns.

Answer 6

Ultraviolet because as we know
E=hf , E = h c / λ and λIR> λuv.

Question 7

If the wavelength is doubled what happens to the energy of the photons?

Answer 7

reduced to half.

Question 8

What happens to the no of electrons if wavelength is increased?

Answer 8

nothing.No of electrons depend upon the intensity of light not wavelength.

Question 9

Formulas

Answer 9

hf=hfnod+K.E
Φnod=hfnod
6.4x10^18 to change joule into eV.