Two current-carrying wires are parallel to one another and separated by 1 cm. If the distance between them is increased to 2 cm the new force will be what factor times the original force?
A) ¼
B) ½
C) 1
D) 2
E) 4

Question

Quizplus · Accepted Answer

According to the formula for the force between two parallel current-carrying wires, the force is inversely proportional to the distance between them. So, if the distance is doubled from 1 cm to 2 cm, the force will decrease by a factor of 2 (i.e. it will become half). Therefore, the new force will be half or 1/2 times the original force. Hence, the answer is B.

Two Current-Carrying Wires Are Parallel to One Another and Separated