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(c) Earth wire carries a part of electric current to the earth so as to save the electrical appliances from damage. We earth the metallic body of an electric appliance to save ourselves from electric shocks. If accidently the live wire touches the metal-case of the electric appliance that has been earthed, the current flows directly into the earth and we are saved from the electric shock.

Or

(a) Name the electrical device which converts electrical energy into mechanical energy. State the principle involved in this device.
(b) In the given circuit, calculate :

(i) the total resistance of the circuit,
(ii) current flowing through the circuit,
(iii) potential difference across the lamp and the resistor.

Ans. (a) Electric motor is a device which converts electrical energy into mechanical energy. An electric motor works on the principle that when a coil carrying current is held in a magnetic field, it experiences
a force which rotates the coil. The rotational direction of the coil is given by Fleming’s Left hand rule.

Science 2008 Question Papers Class X
Delhi		Outside Delhi		Compartment Delhi		Compartment Outside Delhi
	All Sets (PDF)				Set 1		Set 1
					Set 2		Set 2
					Set 3		Set 3