Question

A current-carrying wire in a magnetic field is subject to a magnetic force. If the current in the wire is doubled, what happens to the magnetic force acting on the wire?

• A. It is quartered
• B. It is halved
• C. It is unchange
• D. It is doubled
• E. It is quadrupled

Answer 1

Answer: (D)

It is doubled

The magnetic force on current $I$ carrying wire of length $L$ in the magnetic field $\overrightarrow{B}$ is $\overrightarrow{F}=BIL$

Thus, force is proportional to current.

So when current $I$ is doubled, the force will be doubled.