Advertisements
Advertisements
प्रश्न
In torches, search lights and headlights of vehicles the bulb is placed ______.
विकल्प
between the pole and the focus of the reflector
very near to the focus of the reflector
between the focus and centre of curvature of the reflector
at the centre of curvature of the reflector
Advertisements
उत्तर
In torches, search lights and headlights of vehicles the bulb is placed very near to the focus of the reflector.
Explanation -
In torches, search lights and headlights of vehicles concave mirrors are used. When a light source is placed at the focus of the mirror, after reflection light rays become parallel to the principal axis. Due to this, the bulb is placed very near to the focus of the reflector.
संबंधित प्रश्न
A ray of light is incident on a plane mirror at an angle of 30°. What is the angle of reflection
What type of image is formed:
- in a plane mirror?
- on a cinema screen?
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
What will be the focal length of this mirror?
What do you understand by the focus and focal length of a spherical mirror? Show them on the separate diagrams for each of a concave mirror and a convex mirror.
How is a spherical mirror used to converge a beam of light at a point? Name the type of mirror used.
An optical device has been given to a student and he determines its focal length by focusing the image of the sun on a screen placed 24 cm from the device on the same side as the sun. Select the correct statement about the device.
(A) Convex mirror of focal length 12 cm
(B) Convex lens of focal length 24 cm
(C) Concave mirror of focal length 24 cm
(D) Convex lens of focal length 12 cm
State whether the image in part (a) is real or virtual?
Which mirror will you prefer to use as a rear view mirror in a car : plane mirror or convex mirror? Give one reason.
The focal length of a concave mirror is 10 cm. Find its radius of curvature.
A concave mirror forms a virtual image of size twice that of the object placed at a distance 5 cm from it. Find:
- the focal length of the mirror
- position of image
Answer the following question:
Distinguish between the convex mirror and the concave mirror.
Define the following term in relation to concave mirror.
Pole
Geometric centre of the spherical mirror is ______.
A shopkeeper wanted to fix a mirror which will give a maximum view of his shop. What type of mirror should he use? Give reason.
Define the following terms in the context of a diverging mirror:
- Principal focus
- Focal length
Draw a labelled ray diagram to illustrate your answer.
