What is the function of an earth wire? Why is it necessary to earth metallic appliances?

When does an electric short circuit occur?

State the rules for finding the direction, when :(a) A magnetic field produced around a straight conductor carrying current,(b) The force experienced by a current carrying a straight conductor placed in a magnetic field placed perpendicular to it.(c) current induced in a coil due to its rotation in a magnetic field.

Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from the back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of the magnetic field?

When is the force experienced by a current–carrying conductor placed in a magnetic field largest?

State whether the following statements are true or false : (a) The field at the center of a long circular coil carrying current will be parallel straight lines. (b) A wire with green insulation is usually the live wire of an electric supply

At the time of the short circuit, the current in circuit : (a) reduces substantially (b) does not change (c) increases heavily (d) vary continuously

Which of the following correctly describes the magnetic field near a long straight wire? (a) The field consists of straight lines perpendicular to the wire. (b) The field consists of straight lines parallel to the wire. (c) The field consists of radial lines originating from the wire. (d) The field consists of concentric circles centred on the wire.

What precautions should be taken to avoid the overloading of domestic electric circuits?

An electric oven with 2 kW power rating is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain.

Name two safety measures commonly used in electric circuits and appliances.

A positively-charged particle (alpha-particle) projected towards the west is deflected towards the north by a magnetic field. The direction of magnetic field is : (a) towards south (b) towards east (c) downward (d) upward

In Activity 13.9, how do we think the displacement of rod AB will be affected if (i) the current in rod AB is increased; (ii) a stronger horse-shoe magnet is used, and (iii) the length of the rod AB is increased?

Which one of the following properties of a proton changes while moving freely in a magnetic field? (a) Mass (b) Speed (c) Velocity (d) Impulse

Choose the correct option. The magnetic field inside a long straight solenoid-carrying current : (a) is zero. (b) decreases as we move towards its end. (c) increases as we move towards its end. (d) is the same at all points.

The magnetic field in a given region is uniform. Draw a diagram to represent it

Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.

Why don’t two magnetic field lines intersect each other?

List the properties of magnetic field lines.

Draw magnetic field lines around a bar magnet

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