SATHEE: Dual Nature of Radiation and Matter

Dual Nature of Radiation and Matter - Result Question 51

54. A photoelectric cell is illuminated by a point source of light $1 m$ away. When the source is shifted to $2 m$ then

[2003]

(a) number of electrons emitted is a quarter of the initial number

(b) each emitted electron carries one quarter of the initial energy

(d) each emitted electron carries half the initial energy

Show Answer

Answer:

Correct Answer: 54. (a)

Solution:

(a) Intensity $\propto$ No. of electrons emitted (N)

$I \propto \frac{1}{r^{2}} \Rightarrow N \propto \frac{1}{r^{2}}$

Energy crossing per unit area normally per second is called Intensity.

$I = \frac{E}{A t} = \frac{P}{A} (.$ Here, $P = \frac{E}{t} =$ radiation power $)$

At a distance $r$ from a point source of power $P$

intensity is given by $I = \frac{P}{4 π r^{2}}$

$\Rightarrow I \propto \frac{1}{r^{2}}$

Play Store

App Store

Ask SATHEE

Welcome to SATHEE !
Select from 'Menu' to explore our services, or ask SATHEE to get started. Let's embark on this journey of growth together! 🌐📚🚀🎓

I'm relatively new and can sometimes make mistakes.
If you notice any error, such as an incorrect solution, please use the thumbs down icon to aid my learning.
To begin your journey now, click on "I understand".

Dual Nature of Radiation and Matter - Result Question 51

54. A photoelectric cell is illuminated by a point source of light 1m away. When the source is shifted to 2m then

Answer:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

Menu

54. A photoelectric cell is illuminated by a point source of light $1 m$ away. When the source is shifted to $2 m$ then