MEDIUM
JEE Main
IMPORTANT
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A certain type of glass has an index of refraction of 1.62 for red light. (a) At what angle will light (in air) be completely polarized when reflected by the glass? (b) Will the reflection angle for complete polarization of blue light be larger or smaller?

Important Questions on Electromagnetic Waves

MEDIUM
JEE Main
IMPORTANT

In the figure, the light is incident at an angle θ1=40.1° on a boundary between two transparent materials. Some of the light travels down through the next three layers of transparent materials, while some of it reflects upward and then escapes into the air. If n1=1.30, n2=1.40n3=1.32 and n4=1.75, what is the value of (a) θ5 in the air and (b) θ4 in the bottom material?

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HARD
JEE Main
IMPORTANT

An isotropic point source emits light at wavelength 500 nm at the rate of 300 W. A light detector is positioned 400 m from the source. What is the maximum rate Bt at which the magnetic component of the light changes with time at the detector's location?

MEDIUM
JEE Main
IMPORTANT

Dispersion in a window pane. In the figure (a), a beam of white light is incident at angle θ=40° on a common window pane (shown in cross section). For the pane's type of glass, the index of refraction for visible light ranges from 1.524 at the blue end of the spectrum to 1.509 at the red end. The two sides of the pane are parallel. What is the angular spread of the colors in the beam (a) when the light enters the pane and (b) when it emerges from the opposite side? (Hint: When you look at an object through a window pane are the colors in the light from the object dispersed as shown in figure (b, c)?)

(a)

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(b) 

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(c) Question Image

HARD
JEE Main
IMPORTANT

In the figure, a ray of light is perpendicular to the face ab (n=1.81). Find the largest value for the angle ϕ, so that the ray is totally reflected at face ac if the prism is immersed (a) in air and (b) in water.

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HARD
JEE Main
IMPORTANT
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?
EASY
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.
HARD
JEE Main
IMPORTANT

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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HARD
JEE Main
IMPORTANT

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