20 cm high object is placed at a distance of 25 cm from a converging lens of focal length of 10 cm . Determine the position , size and type of the image .

20 cm high object is placed at a distance of 25 cm from a converging l

1.	20 cm high object is placed at a distance of 25 cm from a converging lens of focal length of 10 cm . Determine the position , size and type of the image .
Answer» Solution :Date: Converging lens, F= 10 , u =-25 cm `h_1 =5 cm`v=? `h_2 = ? ` (i) `1/f = 1/v-1/u :. 1/ v= 1/f + 1/u` `:. 1/v = 1/(10 cm) + 1/(-25 cm ) = 1/(10 cm )-1/(25 cm ) ` `= (5-2)/( 50 cm ) =3/(50 cm ) ` `:.` Image DISTANCE ,` v = 50 / 3 cm ` ` div 16.67 cm div 16.7 cm `This gives the position of the image. (ii) ` h_2 /h_1 = v/ u:. h_2 = v/u h_1 ` ` THEREFORE h_2 =((50/3) cm )/(-25 CM ) xx 20 cm =- ( 50 xx 20)/(25 xx 3) cm` `=- 40/3 cm div - 13.333 cm ` ` div - 13.3 ` cm The height of the image =- 13.3 cm ( inverted image ) ` ` therefore ` minus sign . (III)The image is real , invreted and smaller than the OBJECT .