Question

A wire carrying a current of 5 A is placed perpendicular to a magnetic induction of 2T. The force on each centimeter of the wire is :

• A. 0.1 N
• B. 10 N
• C. 100 N
• D. 1N

Answer 1

The correct option is A 0.1 N

Answer is A.

The relationship between the current through the conductor, length of the wire and the smaller angle between velocity v and magnetic field B is given as : $F=ILBsin\theta$.
In this case, the conductor, that is, wire is perpendicular to the magnetic field. $\theta$ = 90 degrees.
Substituting, I = 5 A, L = 1 centimeter, that is, 0.01 m, B = 2 T and $\theta$ = 90 degrees in the above expression we get,
$F=5\times 0.01\times 2\times 1=0.1N$.
Hence, The force on each centimeter of the wire is 0.1 N.