A point charge is moving in clockwise direction in a circle with constant speed. Consider the magnetic field produced by the charge at a fiexed point P (not at the centre of circle ) on the axis of the circle. Then,

Options

A. it is constant in magnitude only
B. it is constant in direction only
C. it is constant in direction and magnitude both
D. it is not constant in magintude and direction both

Answer

A

Explanation

the point charge moves in circule as shown in figure the magnetic field vectors at a point P on axis of circle ase `vec(B_(A)) and vec(B_(C))` at the instants the point charge si at A and C respectively as shown in the figure

Hence as the particles rotates in circle only magnitude fiels remains constant at the point on axis P but its direction changes .
`implies` Alternate solution
`implies` the magnetic field at point on the axis due to given by
`(mu_(0))/(4pi)(qvecvxxvecr)/(r^(3))`
it can can be seen the magnitude of the magnetic fleld at on point on the axis remains constant .But the direction of the keeps changing .