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Ans. (a) Magnetic field produced by a current carrying circular coil.
(i) A rectangular card board having holes is taken and a circular coil having large number of turns is
inserted in the cardboard. The coil should be inserted in the cardboard in such a manner that the
coil is normal to the plane of the cardboard.

(ii) The ends of the coil are connected in series with a battery, a key and a rheostat.

(iii) Then iron filings are sprinkled uniformly on the cardboard.

(iv) Now the key is plugged.

(v) On tapping the cardboard gently, the circular magnetic field lines near the current carrying loop are observed. On moving away from the circular loop, the concentric circles representing magnetic field lines become bigger and bigger. At the centre of the circular loop, the magnetic field lines are straight. Also See Q.12, 2004 (Outside Delhi). [Page P-10

(b) The earth wire is used as a safety measure for electrical appliances having a metallic body. e.g., electric press, toaster, table fan, refrigerator etc. The earth wire, which has insulation of green colour is usually connected to a metal plate dug deep inside the earth near the house. The leaked current from the appliance passes directly to the earth through the earth wire. Actually a very heavy current flows through the earth wire and the fuse of household wiring melts and cuts off the power supply. The appliance having metallic body is connected to the earth wire as it provides a low-resistance conducting path for the current. Thus it ensures that any leakage of current to the metallic body of the appliance keeps its potential to that of the earth, and the user does not get a severe electric shock.

Section B

Q. 17. State what type of method is used for growing jasmine plant. 1

Ans. Layering.

Q. 18. State two changes you can make in your habits to reduce the consumption of electricity or water. 1

Ans. For reducing consumption of electricity:
(i) I will use stairs to climb at least up to three floors of a building instead of taking a lift.
(ii) I will use CFL bulbs and lights instead of traditional lamps which consume more energy.
(iii) To reduce consumption of water, I will close the tap while brushing my teeth and use a bucket of water to have a bath instead of a shower.

Q. 20. Write the name and functions of any two parts of the human hind brain. 2

Ans. Pons, Cerebellum and Medulla are the parts of hind brain

• The pons take part in regulating respiration.

• Cerebellum helps to maintain posture and balance of the body.

Science 2009 Question Papers Class X
Delhi		Outside Delhi		Compartment Delhi		Outside Delhi		Foreign
	Set 1 (PDF)		Set 1 (PDF)		Set 1		Set 1		Set 1 (PDF)
					Set 2		Set 2
					Set 3		Set 3