Chapter 24, Problem 2STP

To determine

To Choose: The correct option.

Answer to Problem 2STP

Option B

Explanation of Solution

Given:

Length of the wire, $l=19\text{cm}\text{= 0}\text{.19 m}$

Strength of Magnetic field, $B=4.1\text{T}$

Force experienced by wire, $F=7.6\text{mN}\text{= 7}\text{.6}\times {\text{10}}^{-3}\text{N}$

Field is perpendicular to the wire. So, $\theta =90°$

Formula used:

Magnetic force on a current carrying wire can be obtained by:

  $F=IlB\sin \theta$

Here, l is the length of wire.

Calculations:

Substitute the values:

  $\begin{array}{c}F=IlB\sin \theta \\ I=\frac{F}{lB\sin \theta }\\ =\frac{7.6\times {10}^{-3}}{0.19\times 4.1\times \sin 90°}\\ =9.8\times {10}^{-3}\text{A}\end{array}$

Conclusion:

Thus, option B is correct.