Science : Ch 13 – Magnetic Effects of Electric Current

Commercial electric motors neglect :

The magnetic feld inside a long straight solenoid carrying current is:

Relative strength of magnetic field at a point in the space adjoining the magnet is shown by the:

By which instrument, the presence of magnetic field be resolved?

A current through a horizontal power line flows from south to North direction. The direction of magnetic field line 0.5m above it is:

The strength of each of magnet reduces to half when it cut along its length into the equal parts magnetic field strength of a solenoid. Polarity of solenoid can be determined by:

In electric motor, to make the coil rotating constantly in the identical direction, current is reversed in the coil after every half rotation by a device called:

The instrument that use to direct electric current in the circuit is known as:

A magnet is moved towards a coil (i) quickly (ii) slowly. The induced potential difference:

A coil of many circular turns of wire wrapped in the shape of a cylinder

Which of the following is not attracted by a magnet:

Commercial electric motors do not use

The phenomenon discovered by Faraday.

The law states that if the forefinger indicates the direction of the magnetic field and thumb shows the direction of motion of conductor, then the middle finger will show the direction of induced current

Two magnetic feld lines never intersect because the resultant force on a north pole at any point can only be in