Calculate the current that gives a charge flow of $150\mathrm{C}$ in a time of $30 \mathrm{s}$.

A car battery is labelled $\text{'}50\mathrm{Ah}\text{'}$. This means that it can supply a current of $50 \mathrm{A}$ for one hour

(a) For how long could the battery supply a continuous current of 200 A needed to start the car?

A car battery is labelled $\text{'}50\mathrm{Ah}\text{'}$. This means that it can supply a current of $50 \mathrm{A}$ for one hour

(b) Calculate the charge that flows past a point in the circuit in this time.

A length of copper wire is joined in series to a length of silver wire of the same diameter. Both wires have a current in them when connected to a battery. Explain how the mean drift velocity of the electrons will change as they travel from the copper into the silver. Electron number densities:

Copper $\mathrm{n}=8.5\times {10}^{28}{ \mathrm{m}}^{-3}$

Silver $\mathrm{n}=5.9\times {10}^{28}{ \mathrm{m}}^{-3}$.