(a)[1]
Define the term ohm.
(b)[2]
A wire is made from a metal whose resistivity is $\rho$. Its length $L$ is increased gradually. Assume that the wire’s volume $V$ stays constant as its length increases. Show that the resistance $R$ of the wire is proportional to $L^2$.
(c(i))[1]
From Fig. 5.2, state the battery e.m.f. $E$.
(c(ii))[3]
From Fig. 5.2, determine the power dissipated in the variable resistor when the current is $5.0\,\text{A}$.
(c(iii))[1]
State what the gradient value represents on this graph.
(i)[1]
From Fig. 5.2, state the battery e.m.f. $E$.
(ii)[3]
From Fig. 5.2, determine the power dissipated in the variable resistor when the current is $5.0\,\text{A}$.
(iii)[1]
State what the gradient represents.