PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 24

EASY

12th CBSE

IMPORTANT

Earn 100

When light of frequency $2.4 \times 10^{15} H z$ , falls on a photosensitive surface, the retarding potential needed to completely stop the emitted photoelectrons is found to be $6.8 V$ . What is the work function in $e V$ of the given photosensitive surface?

Important Questions on Dual Nature of Radiation and Matter

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 25

Ultraviolet radiations of wavelength

800 Å

and

700 Å

, when allowed to fall on a photosensitive surface are found to liberate electrons with maximum kinetic energies of

2 e V

and

4.1 e V

respectively. Calculate the value of Planck's constant.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 26

Find the frequency of light which ejects electrons from a metal surface, fully stopped by a retarding potential of

3.3 V

. If photoelectric emission begins in this metal at a frequency of

8 \times 10^{14} H z

, calculate the work function

(e V)

for this metal. Take

h = 6 .63 \times 10^{- 34} Js

.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 27

When

U V

light of wavelength

300 n m

is incident on a metal plate, a negative potential of

0.59 V

is required to stop the emission of photoelectrons. Calculate the energy of the incident photon and the work function for the metal in

e V

.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 28

A metal has a work function of

2.0 e V

and is illuminated by monochromatic light of wavelength

500 n m

. Calculate (

h = 6 .6 \times 10^{- 34} Js, c = 3 \times 10^{8} m / s

)

The threshold wavelength
The maximum energy of photoelectrons
The stopping potential