CBSE - Electricity

1 Electricity Suppose five resistances, each of 10 ohm, are provided t o you. You are free to get the desired value by combining them. The desired value will lie in between

(1) 2 ohm to 50 ohm
(2) 20 ohm to 40 ohm
(3) 12 ohm to 50 ohm
(4) 10 ohm to 60 ohm

2 Electricity 

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

3 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

4 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%

5 Electricity 

What is the direction of induced current in the loop when the current i in the straight wire is (a) increasing (b) steady-

(1) (a) clockwise (b) zero
(2) (a) anticlockwise (b) clockwise
(3) (a) clockwise (b) anticlockwise
(4) (a) anticlockwise (b) zero

6 Electricity The unit of electrical energy is

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

7 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

8 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.

9 Electricity The value of equivalent resistance between the points A and B in the given circuit, will be –


(1) 6R
(2) 4R/11
(3) 11R/4
(4) R/6

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