K.C.S.E Physics Q & A - MODEL 2007PP2QN15

K.C.S.E Physics Q & A - MODEL 2007PP2QN15

​(a) State Ohm's Law 
(b) The graph in figure 9 shows the current – voltage characteristics of a certain device, X

(i) State with a reason whether the device obeys Ohm's law 
(ii) Determine the resistance of the device, X, when the current through it is 60 mA.
(iii) When the device, X is connected in the circuit below, the voltage across it is 0.70 V.

​Calculate the value of the resistance R. 
(c) The cell in figure 10 has an e.m.f of 2.1 V and negligible internal resistance.

​Determine the
(i) Total resistance in the circuit 
(ii) Current in the circuit 
(iii) Reading of the voltmeter 

answers