1
JEE Main 2020 (Online) 8th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A plane electromagnetic wave of frequency 25 GHz is propagating in vacuum along the z-direction. At a particular point in space and time, the magnetic field is given by $$\overrightarrow B = 5 \times {10^{ - 8}}\widehat jT$$. The corresponding electric field $$\overrightarrow E $$ is (speed of light c = 3 × 108 ms–1)
A
15 $$\widehat i$$V / m
B
-15 $$\widehat i$$V / m
C
1.66 × 10–16 $$\widehat i$$V / m
D
-1.66 × 10–16 $$\widehat i$$V / m
2
JEE Main 2020 (Online) 7th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The electric field of a plane electromagnetic wave is given by
$$\overrightarrow E = {E_0}{{\widehat i + \widehat j} \over {\sqrt 2 }}\cos \left( {kz + \omega t} \right)$$

At t = 0, a positively charged particle is at the point (x, y, z) = $$\left( {0,0,{\pi \over k}} \right)$$.
If its instantaneous velocity at (t = 0) is $${v_0}\widehat k$$ , the force acting on it due to the wave is :
A
parallel to $$\widehat k$$
B
parallel to $${{\widehat i + \widehat j} \over {\sqrt 2 }}$$
C
antiparallel to $${{\widehat i + \widehat j} \over {\sqrt 2 }}$$
D
zero
3
JEE Main 2020 (Online) 7th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
If the magnetic field in a plane electromagnetic wave is given by
$$\overrightarrow B $$ = 3 $$ \times $$ 10-8 sin(1.6 $$ \times $$ 103x + 48 $$ \times $$ 1010t)$$\widehat j$$ T, then what will be expression for electric field ?
A
$$\overrightarrow E $$ = (9sin(1.6 $$ \times $$ 103x + 48 $$ \times $$ 1010t)$$\widehat k$$ V/m)
B
$$\overrightarrow E $$ = (60sin(1.6 $$ \times $$ 103x + 48 $$ \times $$ 1010t)$$\widehat k$$ V/m)
C
$$\overrightarrow E $$ = (3 $$ \times $$ 10-8 sin(1.6 $$ \times $$ 103x + 48 $$ \times $$ 1010t)$$\widehat i$$ V/m)
D
$$\overrightarrow E $$ = (3 $$ \times $$ 10-8 sin(1.6 $$ \times $$ 103x + 48 $$ \times $$ 1010t)$$\widehat j$$ V/m)
4
JEE Main 2019 (Online) 12th April Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A plane electromagnetic wave having a frequency v = 23.9 GHz propagates along the positive z-direction in free space. The peak value of the Electric Field is 60 V/m. Which among the following is the acceptable magnetic field component in the electromagnetic wave ?
A
$$\overrightarrow B $$ = 2 × 10–7 sin(1.5 × 102 x + 0.5 × 1011t) $$\widehat j$$
B
$$\overrightarrow B $$ = 60 sin(0.5 × 103x + 0.5 × 1011t) $$\widehat k$$
C
$$\overrightarrow B $$ = 2 × 10–7 sin(0.5 × 103 z + 1.5 × 1011t) $$\widehat i$$
D
$$\overrightarrow B $$ = 2 × 10–7 sin(0.5 × 103 z - 1.5 × 1011t) $$\widehat i$$
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