CBSE - Electricity

1 Electricity The device used for measuring electric current is

(1) generator
(2) galvanometer
(3) ammeter
(4) motor

2 Electricity The unit of electrical energy is

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

3 Electricity 

An ammeter can read current upto 5 A and it has twenty divisions between the mark 0 and mark 2A on its scale

The least count of the ammeter is

(1) 0.02 A
(2) 0.01 A
(3) 0.2 A
(4) 0.1 A

4 Electricity 

In an experiment on finding equivalent resistance of two resistors in series, four students draw up circuits - which oneis correct ?

5 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

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 Which country is called the country of Wind mills ?

(1) Holland
(2) Britain
(3) India
(4) America

8 Electricity A resistance wire of uniform cross section is in the form of a ring. The two diametrically opposite points are connected through a source of emf via an ammeter. A conducting wire is now connected across AB, A1 B3 & then A2B2 one by one .
If ammeter reads I1 , I2 & I3 respectively :

(1) I1 > I2 > I3
(2)  I3 = I1 > I2
(3) I1 = 0,  I2 > I3 
(4) I3 = 0, I1 < I2

9 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

10 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