(i) An object is placed at a distance of 60 cm from a convex mirror where the magnitication produced is 1/2. Where should the object be placed to get a magnification of 1/3 ? (ii) A small electric lamp is placed at the focus of a convex lens. State the nature of beam of light produced by the lens. Draw a diagram to show this.

(i) An object is placed at a distance of 60 cm from a convex mirror wh

1.	(i) An object is placed at a distance of 60 cm from a convex mirror where the magnitication produced is 1/2. Where should the object be placed to get a magnification of 1/3 ? (ii) A small electric lamp is placed at the focus of a convex lens. State the nature of beam of light produced by the lens. Draw a diagram to show this.
Answer» Solution :(i) `u=-60cm` `m=+1/2` `m=1/u=1/2` `1/1=(-v)/(-60)` `v=30cm` Using MIRROR formula `1/f=1/u+1/v=1/60` `f=60cm` Now `m=1/3:.1/u+1/v=1/fimplies1/(-u)+1/v=1/60` `u=-60cm` (ii) When a SMALL ELECTRIC lamp is placed at the focus of a convex LENS, a paralel beam of LIGHT is produced by the lens. Ray diagram.