Question

The force exerted on a current-carrying wire placed in a magnetic field is zero when the angle between the wire and the direction of magnetic field is

Answer 1

Force on the current-carrying wire:

Force on a current-carrying conductor in a magnetic field is given as:$\mathrm{F}=\mathrm{BILsin\theta }$

Where $\mathrm{B}=$Magnetic flux; $\mathrm{L}=$length of wire; $\mathrm{I}=$current in the wire; $\mathrm{\theta }=$angle between the current and magnetic field.

Since, Force is zero as given.

$$\begin{gathered} \Rightarrow 0=\mathrm{BILsin\theta } \\ \Rightarrow \mathrm{sin\theta }=0 \\ \Rightarrow \mathrm{\theta }=\mathrm{\pi } \end{gathered}$$

Hence, When force is $0$, the angle between the wire and the direction of magnetic field is $\mathrm{\pi }$or $180°$