When the current is switched on through a wire, a compass needle kept nearby gets deflected from its North -South position. Explain.

Why does a compass needle get deflected when brought near a bar magnet ?

Why does a compass needle get deflected when brought near a bar magnet?

An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.

A small compass needle of magnetic moment .m. is free to turn about an axis perpendicular to the direction of uniform magnetic field .B.. The moment of inertia of the needle about the axis is .I.. The needle is slightly disturbed from its stable position and then released. Prove that it executes simple harmonic motion. Hence deduce the expression for its time period.

A straight wire of length pi //2 m is bent into a circular shape.O is the center of the circle so formed and P is a point on its axis which is at a distance 3 times the from O .A current of 1A is passed through it Calculate the magnitude of the magnetic field at the points O and P .