A conductor ABCDE, shaped as shown, carries current I. It is placed in the x-y plane with the end A and E on the x-axis. A uniform magnetic field of magnitude B exists in the region. The force acting on it will be

Options

A. zero, if B is in the x-direction
B. `lambdaBI` in the z-direction, if B is in the y-direction
C. `lambdaBI` in the negative y-direction,if B is in the z-direction
D. `lambdaaBI`, if B is in the x-direction

Answer

(a,b,c)

Explanation

To find the Ampere's force on a conductor of any shape, replace
the conductor by an imagninary straight conductor joining the
two ends of the given conductor. So, if B is in x-direction, then
the imaginary staright conductor will be along the field and the
force acting on it will be zero. If B is in y direction, then the force
will be `lambdaBI` acting along the x direction. Similarly, if B is in the
z direction, then the force will be `lambdaBI`, acting along the negative
y direction.