PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 5

MEDIUM

12th CBSE

IMPORTANT

Earn 100

Find the number of photons emitted per minute by a $25 W$ source of monochromatic light of wavelength $5000 Å$ . Take, $c = 3 \times 10^{8} m s^{- 1}$

Important Questions on Dual Nature of Radiation and Matter

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 6

The work function

W_{0}

of a metal

X

equals

3 \times 10^{- 19} J

. Calculate the number

(N)

of photons of light of wavelength

2652 n m

, whose total energy equals

W_{0}

. Take,

c = 3 \times 10^{8} m / s

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 7

Calculate the frequency of a photon of energy

0.5 k e V

. Given

h = 6.62 \times 10^{- 34} J s

.

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 8

Monochromatic light of frequency

5.0 \times 10^{14} H z

is produced by a laser. The power emitted is

3.0 \times 10^{- 3} W

. Estimate the number of photons emitted per second on an average by the source. Take

h = 6 .626 \times 10^{- 34} Js

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 9

A monochromatic source of light operating at

200 W

emits

4 \times 10^{20}

photons per second. Find the wavelength of the light. Take:

h = 6 .63 \times 10^{- 34} Js, c = 3 \times 10^{8} m / s

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 10

If a photoemissive surface has a threshold frequency of

4.6 \times 10^{14} H z

. Calculate the energy of the photons in

e V

. Given

h = 6.6 \times 10^{- 34} J s

.

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 11

Calculate the longest wavelength of the incident radiation, which will eject photoelectrons from a metal surface, whose work function is

3 eV

. Take:

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

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 12

Metal has a threshold wavelength of

6000 Å

. Calculate threshold frequency and work function of the metal in

e V

. Given

h = 6.62 \times 10^{- 34} J s

and charge of electron,

e = 1.6 \times 10^{- 19} C

and speed of light,

c = 3 \times 10^{8} m / s

.

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 3 - Dual Nature of Radiation and Matter>Problems For Practice>Q 13

Calculate the threshold frequency of photon for photoelectric emission from a metal of work function

0.1 e V .

Take,

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