Two long and parallel straight wires A and B carrying currents of \(8.0\) A and \(5.0\) A in the same direction are separated by a distance of \(4.0\) cm. The force on a \(10\) cm section of wire A is:
1. | \(3\times10^{-5}\) N | 2. | \(2\times10^{-5}\) N |
3. | \(3\times10^{-4}\) N | 4. | \(2\times10^{-4}\) N |
The wires which connect the battery of an automobile to its starting motor carry a current of \(300~\text{A}\) (for a short time). What is the force per unit length between the wires if they are \(70~\text{cm}\) long and \(1.5~\text{cm}\) apart?
1. \(2.2~\text{N/m}\)
2. \(4.7~\text{N/m}\)
3. \(3.2~\text{N/m}\)
4. \(1.2~\text{N/m}\)