JEE Main · 2023 · 29 Jan 2023 · Shift 2 · EM Waves

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Given below are two statements:
Statement I: Electromagnetic waves are not deflected by electric and magnetic field.
Statement II: The amplitude of electric field and the magnetic field in electromagnetic waves are related to each other as

E_{0} = \frac{μ _{0}}{ε _{0}} B_{0}

In the light of the above statements, choose the correct answer from the options given below:

(A)Statement I is true but statement II is false✓ Correct
(B)Both Statement I and Statement II are true
(C)Statement I is false but statement II is true
(D)Both Statement I and Statement II are false

Answer: (A)

Solution

An electromagnetic wave carries no net charge, so a static electric or magnetic field exerts no net force on it and cannot deflect it, which makes the first statement sound. For the field amplitudes, the electric and magnetic parts of the wave are tied together through the speed of light,

E_{0} = c B_{0} = \frac{1}{μ _{0} ε _{0}} B_{0}

. The quantity

μ_{0} / ε_{0}

is the impedance of free space, not its speed, so the relation quoted in the second statement is wrong. The first statement is true while the second is false.

JEE Main · 2023 · 29 Jan 2023 · Shift 2 · Single correct option

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JEE Main · 2023 · 29 Jan 2023 · Shift 2 · EM Waves

Solution

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