question_answer 7)

The values of current, I, flowing in a given resistor for the corresponding values of potential difference, V, across the resistor are given below : I (ampere)       :           0.5       1.0       2.0       3.0       4.0 V (volt)            :           1.6       3.4       6.7       10.2    13.2 Plot a graph between V and I and calculate the resistance of the resistor.

Answer:

The V-I graph is as shown in fig. For V = 4V (i.e., 9V ? 5V), I = 1.25 A (i.e., 2.65 A ? 1.40 A). Therefore, R =  = 3.2 The value of R obtained from the graph depends upon the accuracy with which the graph is plotted.