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LAKSHYA JEE (2024)
Ray Optics
1.
A point source is placed at a depth h below the
surface of water (refractive index = µ). The medium
above the surface of water is air (µ =1). Find the area
on the surface of water through which light comes in
air from water.
(1)
 h2
( 2r )
(2)
(3)
h
(  2 – 1)
(4)
4.
2 h 2
( r )
DPP-09
A ray of white light is incident on an interface
between glass and air from glass towards air. The
angle of incidence is such that the green light just
suffers total internal reflection. The ray of light
emerging from glass to air contains:
(1)
Red, Orange and Yellow colours
(2)
Violet, Indigo and Blue colour
(3)
All colours
(4)
All colours except Green
2
2.
3.
None of these
Light goes from glass (µ = 3/2) to air. Find the angle
of incidence for which the angle of deviation is 90º.
(1) 45°
(2) 30°
(3) 15°
(4) None of these
A transparent solid cylindrical rod has a refractive
2
. It is surrounded by air. A light ray is
index of
3
incident at the mid-point of one end of the rod as
shown in the figure. The incident angle () for which
the light ray grazes along the wall of the rod is
(1)
 3
sin −1 

 2 
(2)
 2 
sin −1 

 3
(3)
 1 
sin −1 

 3
(4)
1
sin −1  
2
5.
A fish looks upwards at an unobstructed overcast sky.
What total angle does the sky appear to subtend? (Take
refractive index of water is 2 )
(1) 180º
(2) 90º
(3) 75º
(4) 60º
6.
White light is incident on the interface of glass and
air as shown in the figure. If green light is just totally
internally reflected then the emerging ray in air
contains
(1)
(2)
(3)
(4)
Yellow, orange, red
Violet, indigo, blue
All colours
All colours except green
2
7.
The critical angle of a medium with respect to air is
45°. The refractive index of medium is
(1) 1.41
(2) 1.2
(3) 1.5
(4) 2
8.
If the critical angle for total internal reflection from a
medium to vacuum is 30°, the velocity of light in the
medium is
(1) 3 ×108 m/s
(2) 1.5 ×108 m/s
(3)
9.
6 ×108 m/s
(4)
3 108 m / s
A light ray travelling in glass medium is incident on
glass-air interface at an angle of incidence θ. The
reflected (R) and transmitted (T) intensities, both as
function of θ, are plotted. The correct sketch is
(1)
(2)
(3)
(4)
10.
In the shown figure, the minimum value of i so that
total internal reflection never takes place at P.
(1)
cos–1[ 8 /17]
(2)
sin–1[ 8 /17]
(3)
cos–1[ 17 /8]
(4)
sin –1[ 17 / 8]
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Note: Kindly find the Video Solution of DPPs Questions in the DPPs Section.
Answer Key
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2.
3.
4.
5.
(3)
(1)
(3)
(1)
(2)
6.
7.
8.
9.
10.
(1)
(1)
(2)
(3)
(4)
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