Alternative A

 

Question 3A

 

 

 

The circuit diagram above illustrates a set-up to determine the internal resistance of a cell of e.m.f., E = 1.5 V.  The cell is connected with ammeter, A, a resistance box Rband the key, k, in series.                                                                              
With the resistance box sex at R and the key closed, the current I in the circuit is read and recorded.
The procedure is repeated for five other values of R and in each case, the corresponding values of I are recorded.
Fig. 3(a) and Fig. 3(b) on page 12, show Ri and Ii respectively where i=1,2,3,4, 5 and 6.
(i)  Read and record Riand the corresponding Ii.

 

(iii)Tabulate your readings.
(iv)Plot a graph of P on the vertical axis and R on the horizontal axisstarting both axes from the origin (0, 0).
(v) Determine the slope, s, of the graph and the intercept, c, on the vertical axis.

 (vi) State two precautions you would have taken if you were to perform this experiment in the laboratory.