Q. Through two parallel wires $A\ and\ B$, 10A and 2A of currents are passed respectively in opposite directions. If the wire $A$ is infinitely long and the length of the wire $B$ is 2m, then force on the conductor $B$, which is situated at 10 cm distance from $A$, will be
A) $8\ \times 10^{- 7}$ N
B) $8\ \times 10^{- 5}$ N
C) $4\ \times 10^{- 7}$ N
D) $4\ \times 10^{- 5}$ N
Explanation
(b) $F = \ \frac{\mu_{0}}{4\pi}\ \frac{2i_{1}i_{2}}{r}l$
$= \ \frac{10^{- 7} \times 2 \times 10 \times 2}{0.1} \times 2 = 8 \times 10^{- 5}$ N
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.