A current carrying straight wire is kept along the axis of a circular loop carrying a current. The straight wire

Question

Q. A current-carrying, straight wire is kept along the axis of a circular loop carrying a current. This straight wire
(a) will exert an inward force on the circular loop
(b) will exert an outward force on the circular loop
(c) will not exert any force on the circular loop
(d) will exert a force on the circular loop parallel to itself.

Answer 1

The figure shows that, magnetic field due to straight wire is either parallel or antiparallel to the current flow in loop depending on direction of current in wire. Thus force

FF exerted by this magnetic field

BB is

F = Idl × B =IdlBsinθ=0[∵θ=0or180]