K.C.S.E Physics Q & A - MODEL 2015PP2QN18

K.C.S.E Physics Q & A - MODEL 2015PP2QN18

​(a) Three resistors of resistance 2 ohms, 3 ohms and 4 ohms are to be connected to a cell such that they have the least effective resistance.
(I) Draw a circuit diagram to show how they can be connected to achieve this. 
(ii) Determine the least effective resistance of the three resistors. 

​(b) A real object of height 1 cm placed 50 mm from a converging lens forms a virtual image 100 mm from the lens.
(i) Determine the:
(I) focal length of the lens; 
(II) magnification.
(ii) On the grid provided draw to scale the ray diagram for the set up, to show how the image is formed. 

answers