Physics (AS & A Level) · May / June 2022 · Paper 12 · Question 31

The diagram shows a metal block. The block has sides of length \(a\), \(b\) and \(c\) as shown, and its volume is \(V\). Each charge carrier has a charge \(-q\) and the number density of the charge carriers in the metal is \(n\). It takes each charge carrier an average time of \(t\) to pass through the block. What is an expression for the current \(I\)?

1. AI = nqabc
2. BI = \frac{nqV}{t}
3. CI = \frac{nqbc}{t}
4. DI = nqaV

As printed in the paper