A particle is moved in`x-y` plane form `(a,0)` to `(0,a)` along circular arc having centre at origin. Work done by a force `(-ky)/((x^(2)+y^(2))^(3/2))hat(i)+(kx)/((x^(2)+y^(2))^(3/2))hat(j)` on the particle during this motion will be

Options

A. zero
B. `(kpi)/(2a)`
C. `(kpi)/(4a)`
D. none

Answer

B

Explanation

This force is tangential and constant magnitude done will be product of force and distance.