Question

A rectangular loop carrying a current ` i` is situated near a long straight wire such that the wire is parallel to one of the sides of the loop and is in the plane of the loop . If steady current ` I` is established in the wire as shown in the figure ,

A. Rotate about an axis parallel to the wire
B. Move away from the wire or towards right
C. Move towards the wire
D. Remain stationary

Answer 1

Correct Answer - C
The force of attractio/repulsion for current carrying conductors is
`F = (mu_(0))/(2pi) (i_(1) i_(2))/(r) l`,
where `r` is distance between counductors,
`implies F prop (1)/(r)`
Hence, lesser the distance, more is the force.

`r_(1) lt r_(2)`
So `F_(1) gt F_(2)`
`implies F_("net") = (F_(1) - F_(2))` towards the wire.