A semi circular current carrying wire having radius R is placed in x-y plane with its centre at origin ‘O’. There is non-uniform magnetic field `vecB=(B_(0)x)/(2R)hatk` (here `B_(0)` is +ve constant) is existing in the region. The magnetic force acting on semi circular wire will be along:

Options

A. negative x-axis
B. positive x-axis
C. negative y-axis
D. positive y-axis

Answer

A

Explanation

The direction of forces on the two elements taken symmetrical on two sides of the y-axis are shown. Clearly the net force will be on negative x-axis.