1
JEE Main 2022 (Online) 24th June Evening Shift
+4
-1

An electric bulb is rated as 200 W. What will be the peak magnetic field at 4 m distance produced by the radiations coming from this bulb? Consider this bulb as a point source with 3.5% efficiency.

A
1.19 $$\times$$ 10$$-$$8T
B
1.71 $$\times$$ 10$$-$$8T
C
0.84 $$\times$$ 10$$-$$8T
D
3.36 $$\times$$ 10$$-$$8T
2
JEE Main 2022 (Online) 24th June Morning Shift
+4
-1

A plane electromagnetic wave travels in a medium of relative permeability 1.61 and relative permittivity 6.44. If magnitude of magnetic intensity is 4.5 $$\times$$ 10$$-$$2 Am$$-$$1 at a point, what will be the approximate magnitude of electric field intensity at that point?

(Given : Permeability of free space $$\mu$$0 = 4$$\pi$$ $$\times$$ 10$$-$$7 NA$$-$$2, speed of light in vacuum c = 3 $$\times$$ 108 ms$$-$$1)

A
16.96 Vm$$-$$1
B
2.25 $$\times$$ 10$$-$$2 Vm$$-$$1
C
8.48 Vm$$-$$1
D
6.75 $$\times$$ 106 Vm$$-$$1
3
JEE Main 2021 (Online) 1st September Evening Shift
+4
-1
Electric field of plane electromagnetic wave propagating through a non-magnetic medium is given by

E = 20cos(2 $$\times$$ 1010 t $$-$$ 200x) V/m. The dielectric constant of the medium is equal to : (Take $$\mu$$r = 1)
A
9
B
2
C
$${1 \over 3}$$
D
3
4
JEE Main 2021 (Online) 31st August Evening Shift
+4
-1
The magnetic field vector of an electromagnetic wave is given by $$B = {B_0}{{\widehat i + \widehat j} \over {\sqrt 2 }}\cos (kz - \omega t)$$; where $$\widehat i,\widehat j$$ represents unit vector along x and y-axis respectively. At t = 0s, two electric charges q1 of 4$$\pi$$ coulomb and q2 of 2$$\pi$$ coulomb located at $$\left( {0,0,{\pi \over k}} \right)$$ and $$\left( {0,0,{{3\pi } \over k}} \right)$$, respectively, have the same velocity of 0.5 c $$\widehat i$$, (where c is the velocity of light). The ratio of the force acting on charge q1 to q2 is :-
A
$$2\sqrt 2 :1$$
B
$$1:\sqrt 2$$
C
2 : 1
D
$$\sqrt 2 :1$$
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