MEDIUM
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Assertion: The mirror used in search light are parabolic and not concave spherical.

Reason: In a concave spherical mirror the image formed is always virtual.

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Important Questions on Reflection of Light

HARD
A concave mirror has radius of curvature of 40 cm. It is at the bottom of a glass that has water filled up to 5 cm (see figure). If a small particle is floating on the surface of water, its image as seen, from directly above the glass, is at a distance d from the surface of water. The value of d is close to: (Refractive index of water =1.33)
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HARD
A concave mirror of radius of curvature R has a circular outline of radius r. A circular disc is to be placed normal to the axis at the focus so that it collects all the light that is reflected from the mirror from a beam parallel to the axis. For rR , the area of this disc has to be at least
MEDIUM
To find the focal length of a convex mirror, a student records the following data:
Object pin Convex Lens Convex Mirror Image Pin
22.2 cm 32.2 cm 45.8 cm 71.2 cm
The focal length of the convex lens is f1 and that of mirror is f2 . Then taking index correction to be negligibly small, f1 and f2 are close to:
MEDIUM

A point object is moving uniformly towards the pole of a concave mirror of focal length 25 cm along its axis as shown below. The speed of the object is 1 ms-1. At t=0, the distance of the object from the mirror is 50 cm. The average velocity of the image formed by the mirror between time t=0 and t=0.25 s is:

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MEDIUM
A flat mirror revolves at a constant angular velocity making n=0.4 revolutions per second. With what velocity (in m s-1) will a light spot move along a spherical screen with a radius of 15 m, if the mirror is at the centre of curvature of the screen?
MEDIUM
A concave mirror for face viewing has a focal length of 0.4 m. The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is
HARD

A hemispherical glass body of radius 10 cm and refractive index 1.5 is silvered on its curved surface. A small air bubble is 6 cm below the flat surface inside it along the axis. The position of the image of the air bubble made by the mirror is seen :

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MEDIUM
An object is placed on the principal axis of a concave mirror at a distance of 1.5f (f is the focal length). The image will be at,
HARD
A ray of light, travelling in the direction 12i^+3 j^, is incident on a plane mirror. After reflection, it travels along the direction 12i^-3 j^. The angle of incidence is
EASY

A mirror is placed at an angled of 30° with respect to y-axis (see figure). A light ray travelling in the negative y-direction strikes the mirror. The direction of the reflected ray is given by the vector

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MEDIUM
Match the corresponding entries of column 1 with column 2. [Where m is the magnification produced by the mirror]
  Column 1   Column 2
(A) m=-2 (a) Convex mirror
(B) m=-12 (b) Concave mirror
(C) m=+2 (c) Real image
(D) m=+12 (d) Virtual image
MEDIUM
A 1 cm height needle is placed at a distance of 0.1 m from a convex mirror of focal length 0.05 m, then size of the image is
EASY
A concave mirror of focal length 15 cm, forms an image having twice the linear dimensions of the object. The position of the object, when the image is virtual, will be
MEDIUM

A point source of light, S is placed at a distance L in front of the center of plane mirror of width d which is hanging vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror, at a distance 2L as shown below. The distance over which the man can see the image of the light source in the mirror is:

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MEDIUM

A spherical mirror is obtained as shown in the figure from a hollow glass sphere, if an object is positioned in front of the mirror, what will be the nature and magnification of the image of the object? (Figure down as schematic and not to scale)

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HARD
An object, is placed 60 cm in front of a convex mirror of focal length 30 cm. A plane mirror is now placed facing the object in between the object and the convex mirror such that it covers lower half of the convex mirror. What should be the distance of the plane mirror from the object, so that there will be no parallax between the images formed by the two mirrors?
EASY
An object is placed at a distance of 40 cm in front of a concave mirror of focal length 20 cm. The image produced is
EASY
A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L. When the mirror is rotated through a small angle θ, the spot of the light is found to move through a distance y on the scale. The angle θ is given by
MEDIUM
In a car a rear view mirror having a radius of curvature 1.50 m forms a virtual image of a bus located 10.0 m from the mirror. The factor by which the mirror magnifies the size of the bus is close to
MEDIUM
You are asked to design a shaving mirror assuming that a person keeps it at 10 cm from his face and views the magnified image of the face at the closest comfortable distance of 25 cm. The radius of curvature of the mirror would then be: