Question

A 4.0 cm long straight wire carrying a current of 8A is placed perpendicular to an uniform magnetic field of strength 0.15 T. The magnetic force on the wire is ______ mN.

Hint:

Use the formula for the magnetic force on a current-carrying wire in a magnetic field. Remember to convert the length to meters.

Answer 1

Correct Answer: 48

$F = IlB$

$F = 8 \times \frac{4}{100} \times 0.15$

$F = \frac{48 \times 100}{10000} N$

$F = 48 \times 10^{-3} N$

$F = 48 \text{ mN}$