Which one of the following is the natural phenomenon based on which a simple periscope works?
A myopic person has a power of -1.25 Dioptre. What is the focal length and nature of his lens?
Which one of the following processes explains the splitting of a beam of white light into its constituent colours?
Consider the following statements:
A real image
Which of the statements given above is/are correct
An optician prescribes a power = - 0.5 dioptre. The corresponding lens must be a
If the speed of light in air is 3 x 108 m/s, the speed of light in glass (with refractive index 1.5) would be
While looking at the image formed by a convex lens (one half of the lens is covered with black paper), which one of the following will happen to the image?
A person standing in front of a plane mirror approaches the mirror by 40 cm. The new distance between the person and his image in the plane mirror is
An optical illusion which occurs mainly in deserts during hot summer is based on the principle of
A rainbow is produced due to which one of the following phenomena?
Concave mirror is used in headlights of vehicles, because it
The mirrors used as rear-view mirrors in vehicles are
How long does light take to reach the Earth from the Sun?
The focal length of the eye lens increases when eye muscles
When light rays enter the eye, most of the refraction occurs at the
The bluish colour of water in deep sea is due to
Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?
The clear sky appears blue because
Twinkling of stars is due to atmospheric
Which of the following phenomena of light are involved in the formation of a rainbow?
At noon the sun appears white as
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power
A full length image of a distant tall building can definitely be seen by using
Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object?
Magnification produced by a rear view mirror fitted in vehicles
A light ray enters from medium A to medium B as shown in Figure.
The refractive index of medium B relative to A will be
A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is
Which of the following can make a parallel beam of light when light from a point source is incident on it?
Two mirrors A and B are placed at right angles to each other as shown in Figure.
A ray of light incident on mirror A at an angle of 25° falls on mirror B after reflection. The angle of reflection for the ray reflected from mirror B would be
A small hole P is made in a piece of cardboard. The hole is illuminated by a torch as shown in Figure. The pencil of light coming out of the hole falls on a mirror.
At which point should the eye be placed so that the hole can be seen?
Part of the eye which controls the light entering is called
An erect and enlarged image can be formed by
If an object is placed at a distance of 0.5 m in front of a plane mirror, the distance between the object and the image formed by the mirror will be
Which of the following can be used to form a real image?
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