Question

Describe the positions of the source of light with respect to a concave mirror in 1.torch light 2. projector lamp 3. floodlight

Answer 1

Concave mirrors are used as Converging mirrors means they can focus the reflected rays at one point.
Different positions on which the bulb is placed :

In torches :
Sore of light[Bulb] is placed at Focus. So that the rays passing through focus strike the concave mirror and emerge parallel to principal axis so that the light is seen.

In projector lamp:Source of light[The bulb] is placed On C. so that the image is formed of same size .

Flood Lights : The bulb is placed beyond C. 

Answer 2

1) Torch light = The source of light is placed at the focus

2) Projector lamp = The source of light is placed at center of curvature

3) Flood light = The source of light is placed just beyond the center of curvature