What is the function of an earth wire in electrical instruments?

List any two uses of an electromagnet.

Draw a labelled diagram to show how an electromagnet is made.

Describe an activity to demonstrate the direction of the magnetic field generated around a current carrying conductor.

Name one material used for making permanent magnets. Describe how permanent magnets are made electrically.

Describe an activity to draw a magnetic field line outside a bar magnet from one pole to another pole.

(a) What is the function of an earth wire in electrical instruments? Why is it necessary to earth the metallic electric appliances?

(b) Explain what is short-circuiting and overloading in an electric supply.

(c) What is the usual capacity of the fuse wire in the line to feed:

(i) Lights and fans?

(ii) Appliances of 2 kW or more power?

The diagram below shows a coil connected to a centre zero galvanometer G. The galvanometer shows a deflection to the right when the N-pole of a powerful magnet is moved to the right as shown.

(i) Explain why the deflection occurs in the galvanometer.

(ii) Does the direction of current in the coil appear clockwise or anticlockwise when viewed from end A?

(iii) State the observation in G when the coil is moved away from N.

(iv) State the observation in G when, both coil and the magnet, are moved to the right at the same speed.

The figure shows a long solenoid, a cylindrical coil of a number of turns of insulated copper wire, connected to a battery through an ammeter A and a rheostat Rh.

(i) Which end of the solenoid is an N-pole and which end is an S-pole?

(ii) Draw the magnetic field lines inside the solenoid and indicate their directions. Are magnetic field lines closed?

(iii) How can you increase the strength of the magnetic field inside the solenoid? Give two methods.

(a) What is meant by a magnetic field?

(b) How is the direction of magnetic field at a point determined?

(c) Describe an activity to demonstrate the direction of the magnetic field generated around a current carrying conductor.

(d) What is the direction of magnetic field at the centre of a current carrying circular loop?

A current carrying wire produces:

By increasing the number of turns 3 times in a toroidal solenoid, the magnetic field:

The induced potential difference produced, in a coil when a magnet is inserted in it doesn’t depend upon:

The laws of electromagnetism tell us that energy can be transferred from one object to another:

A soft iron bar is introduced inside a current carrying solenoid. The magnetic field inside the solenoid:

Inside a current carrying solenoid the magnetic lines of force are:

The material of the core of a strong electromagnet is:

The direction of induced potential difference is given by:

The principle of which of these devices is electromagnetism:

The magnetic field around a current carrying conductor is:

The strength of the magnetic field of a solenoid does not depend upon:

The phenomenon of electromagnetic induction is:

A device used for producing current is:

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If the direction of current is reversed, the direction of magnetic field is also reversed.

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To find the direction of magnetic field around a current carrying conductor, we use Fleming’s left hand rule.

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Magnetic field due to a straight current-carrying conductor is in the form of concentric circles.

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A current carrying solenoid behaves like a bar magnet.

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Inside a solenoid, the magnetic field is constant in magnitude and direction.

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Magnetic field produced by a current carrying solenoid depends directly upon the strength of the current.

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In order to find the force experienced by a current carrying conductor, we can use Maxwell’s cork screw rule.

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Whenever magnetic field through a coil is changed, a potential difference is produced in the coil.

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The strength of the induced potential difference depends on the relative speed between the coil and the magnet.

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Electric motor converts mechanical energy into electrical energy.

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Fleming’s right hand rule can be used to find the direction of magnetic field.

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Electric generator works on the principle of electromagnetic induction.

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The electric current that always flows in the same direction is called alternating current.

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Normally red colour cable is used for live wire.

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All the distribution circuits for domestic purpose are parallel connections.

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One should always use rubber gloves and rubber shoes when dealing with electricity.

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Earthing of electrical appliances is very important.

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Like magnetic poles attract each other; unlike poles repel.

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If you strike a sharp edge of a metallic knife against the north pole of a bar magnet, it will induce a north pole.

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The magnetic field produced by a current in a straight wire has no poles.

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An electric generator is a device that converts electrical energy into mechanical energy.