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Question : 15
Total: 27
(a) Identify the part of electromagnetic spectrum used in (i) radar and (ii) eye surgery. Write their frequency range.
(b) Prove that the average energy density of the oscillating electric field is equal to that of the oscillating magnetic field.
(b) Prove that the average energy density of the oscillating electric field is equal to that of the oscillating magnetic field.
Solution:
(a) Identification
Frequency range
(b) Proof
Microwaves: Frequency range
( ∼ 10 10 to 10 12 Hz )
Ultraviolet rays: Frequency range
( ∼ 10 15 to 10 17 Hz )
(b) Average energy density of the electric field
=
ε 0 E 2
=
ε 0 ( c B ) 2
=
ε 0
B 2
=
=
Frequency range
(b) Proof
Microwaves: Frequency range
Ultraviolet rays: Frequency range
(b) Average energy density of the electric field
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