Question

In the straight wire A, current is flowing in the vertically downwards direction whereas in wire B the current is flowing in the vertically upward direction. What is the direction of magnetic field:

(a) in wire A?
(b) in wire B?
Name the rule which you have used to get the answer.

Answer 1

We will use right-hand thumb rule to get the answer.

(a) In the straight wire A, current is flowing in vertically downwards direction; therefore, the direction of magnetic field around it will be clockwise.

(b) In the straight wire B, current is flowing in vertically upwards direction; therefore, the direction of magnetic field around it will be anticlockwise.