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The maximum electric field 27 m from an isotropic point source of light is 17 V m-1. What are (a) the maximum value of the magnetic field and (b) the average intensity of the light there? (c) What is the power of the source?

Important Questions on Electromagnetic Waves

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JEE Main
IMPORTANT
Radiation from the sun reaching earth (just outside the atmosphere) has an intensity of 11.4 kW m2. (a) Assuming that earth (and its atmosphere) behaves like a flat disk perpendicular to the sun rays and that all the incident energy is absorbed. Calculate the force on earth due to radiation pressure. (b) For comparison, calculate the ratio of that force to the force due to the sun's gravitational attraction.
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Figure shows the light reflecting from two perpendicular reflecting surfaces A and B. Find the angle between the incoming ray i and the outgoing ray r'.

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In the figure (a), a beam of light in material 1 is incident on a boundary at an angle of θ1=30°. The extent of refraction of the light into material 2 depends on the index of refraction n2 of material 2 . Figure (b) gives the angle of refraction θ2 versus n2 for a range of possible n2 values. The vertical axis scale is set by θ2a=20.0° and θ2b=40.0°. (a) What is the index of refraction of material 1? (b) If the incident angle is changed to 65° and material 2 has n2=2.4, then what is angle θ2?

(a) Question Image

(b) Question Image

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In the figure, a light initially in material 1 refracts into material 2, crosses that material and is then incident at the critical angle on the interface between materials 2 and 3. The indexes of refraction are n1=1.80, n2=1.40 and n3=1.20
(a) What is angle θ?
(b) If θ is increased, is there refraction of light into material 3?

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JEE Main
IMPORTANT
In a plane radio wave, the maximum value of the electric field component is 8.00 V m-1. Calculate (a) the maximum value of the magnetic field component and (b) the wave intensity.
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JEE Main
IMPORTANT
A point source of light is 1.20 m below the surface of a body of water. Find the diameter of the circle at the surface through which light emerges from the water.
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About how far apart must you hold your hands for them to be separated by 1.0 nano-light-second (the distance light travels in 1.0 ns)?
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IMPORTANT

A plane electromagnetic wave with wavelength 5.0 m travels in vacuum in the positive direction of an x-axis. The electric field of amplitude 215 V m oscillates parallel to the y-axis. What are the (a) frequency, (b) angular frequency, and (c) angular wave number of the wave?
(d) What is the amplitude of the magnetic field component?

(e) Parallel to which axis does the magnetic field oscillate?

(f) What is the time-averaged rate of energy flow in watts per square meter associated with this wave? The wave uniformly illuminates a surface of area 2.0 m2. If the surface totally absorbs the wave, what are (g) the rate at which momentum is transferred to the surface and (h) the radiation pressure on the surface?