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JEE Main Physics Class 12 Wave Optics Part 1 Questions
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© examsnet.com
Question : 49
Total: 100
An observer is moving with half the speed of light towards a stationary microwave source emitting waves at frequency 10 GHz. What is the frequency of the microwave measured by the observer? (speed of light
=
3
×
10
8
m
s
–
1
)
[2017]
17.3 GHz
15.3 GHz
10.1 GHz
12.1 GHz
Validate
Solution:
Use relativistic doppler's effect as velocity of observer is not small as compared to light
f
=
f
0
√
c
+
v
c
+
v
;
V
=
relative speed of approach
f
0
=
10
G
H
z
f
=
10
√
c
+
c
2
c
−
c
2
=
10
√
3
=
17.3
G
H
z
© examsnet.com
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