Question

Two parallel wires 2 m apart carry currents of 2 A and 5 A respectively in same direction, the force per unit length acting between these two wires is
A. `2xx 10^(-6)Nm^(-1)`
B. `3xx 10^(-6)Nm^(-1)`
C. `1xx 10^(-6)Nm^(-1)`
D. `4xx 10^(-6)Nm^(-1)`

Answer 1

Correct Answer - C
Given, `I_(1)=2A, I_(2)=5A, r= 2m`
`therefore" "f=(mu_(0))/(4pi)(2I_(1)I_(2))/(r)=10^(-7)xx(2xx2xx5)/(2)=1xx10^(-6)"N m"^(-1)`