K.C.S.E Physics Q & A - MODEL 2012PP2QN017

K.C.S.E Physics Q & A - MODEL 2012PP2QN017

​(a) Figure 16, shows a graph of magnification against object distance, for an object placed infront of a lens of focal length 20cm.

​Using the graph;
(î) State the effect on the size of the image as the object distance is increased from 25cm. 
(ii) Determine the distance between the object and the lens when the image is the same size as the object. 
(iii) Determine the image distance when the object distance is 25 cm. 
(b) Figure 17 shows an object O placed in front of a converging mirror of focal length 15cm.

​Draw on the figure a ray diagram to locate the image formed. 
(c) State why parabolic reflectors are used in car headlights. 

answers

​(c)  A bulb/lamp placed at principal focus will give a wide parallel beam;