CBSE - Electricity

1 Electricity In house electrical circuit s the fuse wire for safety should be of
(1) High resistance - high melting point
(2) Low resistance - high melting point
(3) Low resistance - low melting point
(4) High resistance - low melting point

2 Electricity Out of two bulbs 50 W – 220 V and 100 W –220 V, which one will glow brighter

(a) When connected in series

(b) When connected in parallel

(1) (a) 100 W, (b) 50 W
(2) (a) 50W, (b) 100 W
(3) (a) both will glow similar (b) 100 W
(4) none of t he above

3 Electricity Two wires each carrying current i are shown. The magnetic field at P (midway between the wires) is described by which statement?



(1) Magnetic fields are in opposite direction and net field is equal to zero.
(2) Magnetic fields due to two wires are in the same direction
(3) Magnetic fields are in opposite direct ion but net field is not zero
(4) magnetic fields are in the same direction and equal to two times the field due to one wire.

4 Electricity The unit of electrical energy is

(1) watt
(2) killowatt
(3) kilowatt per hour
(4) kilowatt hour

5 Electricity Alloys are commonly used in electrical heat ing devices, like electric iron etc. because -

(1) Alloys have higher resistivity than that of its constituent metals.
(2) Alloys do not burn at higher temperatures.
(3) Alloys do not oxidise at higher temperatures.
(4) All of above.

6 Electricity If current through a resistance is increased by 100% simultaneously reducing resistance value to 25%, the new power
dissipated will be
(1) No change
(2) Increased by 100%
(3) Decreased by 400%
(4) Increased by 400%

7 Electricity What is the measuring equipment called that measures the electric current passing through conductors?
(1) Wattmeter
(2) Ammeter
(3) Galvanometer
(4) Voltmeter

8 Electricity A certain household has consumed 200 units of energy during a month. Its value in joules will be -

(1) 3.6 × 10¹⁰
(2) 7.2 × 10¹⁰
(3) 3.6 × 10⁸
(4) 7.2 × 10⁸

9 Electricity A comb run through one's dry hair attracts small bits of paper. This is due to :

(1) comb is a good conductor

(2) paper is a good conductor

(3) The atoms in the paper gets polarised by the charged comb

(4) the comb possesses magnetic properties

10 Electricity Out of two bulbs 50W - 220 V and 100W-220V, which one will glow brighter if

(a) connected in series (b) when connected in parallel

(1) (a) 50 W (b) 100 W
(2) (a) 100 W (b) 100 W
(3) (a) 100 W (b) 50 W
(4) none of the above