Question

A power line conducts 10 A current along east-west direction. The magnetic force acting per unit leng
(104)
the line due to earth's magnetic field
is
(A) 10².
(B) 10-'N
(C) 104N
(D) 10-SN

Answer 1

Explanation:

The correct option is C.

Given,

current=10ampere

The magnetic field of 10

−4

tesla

F=B×I×L×sinA

Where, B is the magnetic field, I is the current,L is the length of wire and A is the angle between the magnetic field and the current flow.

Now,

A=90

0

as the south-westward direction which is perpendicula to the earth magnetic field.

L=1

Thus the required force,

F=B×I=0.001×10=10

−3

N