Science : Ch 13 – Magnetic Effects of Electric Current

It is given that the current carrying conductor is held in exactly vertical direction.  In order to produce a clockwise magnetic feld around the conductor, the current should be passed in the conductor from top towards bottom.

Magnetic field is a vector quantity that has both direction and magnitude the direction of the magnetic field is taken to be the direction in which a north pole of the compass needle moves inside it.

An electric motor is a device that converts electric energy into mechanical energy. An electric motor has an electromagnet instead of permanent magnet (as permanent magnet does not produce strong magnetic field).

Brass is not a magnetic material. It is an alloy of copper and zinc

The magnetic field lines inside a long straight solenoid carrying current is in the form of parallel straight lines which indicates that the magnetic field is same at all points inside the solenoid

The force acting on the pole of another magnet by the crowded magnetic field lines is greater.

Apply right-hand thumb rule

If the current direction is parallel to the magnetic field, then there will no force on the conductor exerted by the magnetic field.

A device that reverses the direction of current in the arms of armature through a circuit is called commutation.

A galvanometer is an instrument that can direct the presence of current in a circuit.

When magnet is moved quickly, more will be the changing magnetic field strength and hence larger is the induced potential difference.