JEE PYQ: Electromagnetic Waves Question 1
Question 1 - 2021 (16 Mar 2021 Shift 1)
A plane electromagnetic wave of frequency $500$ MHz is travelling in vacuum along y-direction. At a particular point in space and time, $\vec{B} = 8.0 \times 10^{-8} \hat{z}$ T. The value of electric field at this point is: (speed of light $= 3 \times 10^{8}$ ms$^{-1}$; $\hat{x}, \hat{y}, \hat{z}$ are unit vectors along x, y and z direction.)
(1) $-24\hat{x}$ V/m
(2) $2.6\hat{x}$ V/m
(3) $24\hat{z}$ V/m
(4) $-2.6\hat{y}$ V/m
Show Answer
Answer: (1)
Solution
$f = 5 \times 10^{8}$ Hz. EM wave is travelling towards $+\hat{y}$. $\vec{E} = \vec{B} \times \vec{C} = (8 \times 10^{-8} \hat{z}) \times (3 \times 10^{8} \hat{y}) = -24\hat{x}$ V/m.
BETA
