Parabolic mirrors are used in torches and car headlamps as reflectors. A small lamp is placed at the focus point of the mirror to produce parallel rays.
1. In torches, searchlights and headlights of vehicles the bulb is placed
a. Between the pole and the focus of the reflector.
b. Very near to the focus of the reflector.
c. Between the focus and centre of curvature of the reflector.
d. At the centre of curvature of the reflector.
2. The mirror having reflecting surface curved inwards is
a. Plane mirror
b. Convex mirror
c. Cylindrical mirror
d. Concave mirror
3. Which of the following can make a parallel beam of light when light from a point source is incident on it?
a. Concave mirror as well as convex lens.
b. Convex mirror as well as concave lens.
c. Two plane mirrors placed at 90° to each other.
d. Concave mirror as well as concave lens.
4. State where an object must be placed so that the image formed by a concave mirror is at infinity.
a. Between pole and focus of the mirror.
b. At focus of the mirror.
c. At the centre of curvature.
d. None of these.
5. State where an object must be placed so that the image formed by a concave mirror is the same size as the object.
a. Between pole and focus of the mirror.
b. At focus of the mirror.
c. At the centre of curvature.
d. None of these.
