Home
Class 12
PHYSICS
A plane mirror of circular shape with ra...

A plane mirror of circular shape with radius r = 20 cm is fixed to the celling. A bulb is to be placed on the axis of the mirror. A circular area of the radius R = 1m on the floor is to be illuminated after reflection of light from the mirror. The height of the room is 3m . What is the maximum distance from the centre of the mirror and the bulb so that the required area is illuminated ?

Text Solution

Verified by Experts

The correct Answer is:
75 cm
`DeltaABC ` & `DeltaAB'C`
`(x)/(0.20) = (x+3)/(1)`
x = 0.2x + 0.6`
`0.8x = 0.6 implies x = (3)/(4)` cm
x = 75 cm
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • GEOMETRICAL OPTICS

    ALLEN|Exercise EXERCISE-04[B]|18 Videos

  • GEOMETRICAL OPTICS

    ALLEN|Exercise EXERCISE-05 (A)|35 Videos

  • GEOMETRICAL OPTICS

    ALLEN|Exercise EXERCISE-3|12 Videos

  • CURRENT ELECTRICITY

    ALLEN|Exercise EX.II|66 Videos

  • GRAVITATION

    ALLEN|Exercise EXERCISE 4|9 Videos

Similar Questions

Explore conceptually related problems

A plane mirror of circular shape with radius r=20cm is fixed to the ceiling .A bulb is to be placed on the axis of the mirror.A circular area of radius R=1m on the floor is to be illuminated after reflection of light from the mirror. The height of the room is 3m What is maximum distance from the center of the mirror and the bulb so that the required area is illuminated?

A concave mirror forms an image of 20 cm high object on a screen placed 5.0 m away from the mirror. The height of the image is 50 cm. Find the focal length of the mirror and the distance between the mirror and the object.

Knowledge Check

  • A ray of light after reflection from a mirror is known as

    A
    reflected ray
    B
    normal
    C
    incident ray
    D
    refracted ray

    • Similar Questions

    Explore conceptually related problems

    A convex mirror has its radius of curvature 20 cm. Find the position of the image of an object placed at a distance of 12 cm from the mirror.

    An object is placed at a distance of 20 cm from a concave mirror of focal lenght 10 cm. What is the image distance?

    An object is placed at 20 cm from a convex mirror of focal length 20 cm. The distance of the image from the pole of the mirror is

    The image formed by a concave mirror is twice the size of the object. The focal length of the mirror is 20 cm. The distance of the object from the mirror is//are

    Mention one difference between reflection of light from a plane mirror and total internal reflection of light from a prism.

    You are standing at a distance 2 metre from a plane mirror. What is the distance of your image from the mirror ?

    A particle of mass m is kept on the axis of a fixed circular ring of mass M and radius R at a distance x from the centre of the ring. Find the maximum gravitational force between the ring and the particle.

    Home
    Profile