(a) An increase in current causes an increase in temperature which in turn causes an increase in resistance.
(b) R = $\frac{V}{I} = \frac{2.5}{1.2}$ = 2.08 ohms
(c) From the graph, a current of 0.4 A corresponds to a p.d. of 1 V
johnmulu answered the question on May 23, 2017 at 12:24
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