Question

In the above shown figure, what is the direction of the magnetic force $F_B$ ?

• A. To the right
• B. Downward, in the plane of the page
• C. Upward, in the plane of the page
• D. Out of the plane of the page
• E. Into the plane of the page

Answer 1

The correct option is D Out of the plane of the page

Magnetic force $\overrightarrow{F_B}=-q(\overrightarrow{v}\times \overrightarrow{B})=q(\overrightarrow{B}\times \overrightarrow{v})$

Using right hand thumb rule, we get that $(\overrightarrow{B}\times \overrightarrow{v})$ points in the direction out of the plane of page.

Hence the direction of magnetic force is out of the plane of page.