Question

Use ray diagrams to solve problems 10 –13.

10. An object is 10 cm high and is placed 30 cm in front of a converging lens of focal length 20 cm. Determine the image distance, the image height and the magnification.

11. An object is 10 cm high and is placed 20 cm in front of a converging lens of focal length 20 cm. Determine the image distance, the image height and the magnification.

12. An object is 10 cm high and is placed 16 cm in front of a converging lens of focal length 20 cm. Determine the image distance, the image height and the magnification.

13. An object is 10 cm high and is placed 12 cm in front of a converging lens of focal length 20 cm. Determine the image distance, the image height and the magnification.

Answer 1

Giveni object height(h) = 10cm object distance(s) - 20cm Focal length (f) = 20cm. we know, S' + Y = 48 Y - / AN Ys 7 - Yao / 20 th sasa Infinite. Image distance is Torfine fe. sk Magnifica fim (M)- 20 is : Image height - Infinite ń =hIMI = 10 XA 12 % == Infinite Giveni h = locm s=16cm f = 20cm ..+ Yo - YA 7 % = % - %

3 / 4 = 12 26 - 1/6 16-20 20x16 4 12 320 = -80 cm Image distance is 80cm. " Magnification (M) = -5% IG ... Image height (b) chloul = 10 x 5 - 50cm. 13 ) Giveni h = 10 cm s = 12cm f = 20cm 1.5 Y = 15 / - /s 9 Y! - 712 12 - 20 Fys: 20 7 % 20 X 12 -30em Image distance is 30cm.

Magnification (M) = -5/ -30 12 = 2.5 is. Image height (h) = him1 = 10x2.5 = 25 cm.