ExamBro
ExamBro
CUET · PHYSICS · PYQ PAPER 2023

A plane electromagnetic wave of frequency 75 Hz travels in free space along the X -direction. At a particular point in space and time \(\vec{E}=9.6 \hat{j}\). What is \(\vec{B}\) at that point ?
( \(E=\) Electric field, \(B=\) Magnetic field)

  1. A \(3.2 \times 10^{-8} \hat{k} T\)
  2. B \(3.2 \times 10^{-8} \hat{j} T\)
  3. C \(3.2 \times 10^{-8} \hat{i} T\)
  4. D \(9.6 \hat{j} T\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(3.2 \times 10^{-8} \hat{k} T\)

Step-by-step Solution

Detailed explanation

\(B = \frac{E}{c}\) \(B = \frac{9.6}{3 \times 10^8}\) \(B = 3.2 \times 10^{-8} \text{ T}\) \(\vec{E} \times \vec{B}\) points in X-direction: \(\hat{j} \times \hat{k} = \hat{i}\) \(\vec{B} = 3.2 \times 10^{-8} \hat{k} \text{ T}\)