(a)[1]
State two SI base units besides kilogram, metre and second.
(b)[3]
Determine the SI base units for resistivity.
(c(i))[3]
A wire has cross-sectional area $1.5\,\text{mm}^2$, length $2.5\,\text{m}$, and resistance $0.030\,\Omega$. Calculate the resistivity of the wire material in $\text{n}\Omega\,\text{m}$.
(c(ii).1)[1]
State what precision means.
(c(ii).2)[2]
Explain why measuring the wire’s diameter with a micrometer screw gauge rather than a metre rule improves the precision of the resistivity value.