wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A 5 watt source emits monochromatic light of wavelength 5000. When placed 0.5m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0m, the number of photoelectrons liberated will be reduced by a factor of

A
8
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
16
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
4
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D 4
Power of the source Po=5 W
Power at the distance r from source, P=Po4πr2 .....(1)
Each photon emits one electrons.
Also, PN .....(2)
N is the number of photons (or photo electrons).
From (1) and (2) we get, number of photo electrons N1r2
N2N1=r21r22
Given : r1=0.5 m r2=1 m
N2N1=0.5212=14

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Cathode Ray Experiment
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon