## MCQ Questions for Class 10 Science: Ch 12 Electricity

1. Resistivity of a metallic wise depends on
(a) its length
(b) its shape
(c) its thickness
(d) nature of material
► (d) nature of material

2. A battery of 10 volt carries 20,000 C of charge through a resistance of 20 Ω. The work done in 10 seconds is
(a) 2 × 103 joule
(b) 2 × 105joule
(c) 2 × 104 joule
(d) 2 × 102 joule
► (b) 2 × 105joule

3. To get 2 Ω resistance using only 6 Ω resistors, the number of them required is
(a) 2
(b) 3
(c) 4
(d) 6
► (b) 3

4. The least resistance obtained by using 2 Ω, 4 Ω, 1 Ω and 100 Ω is
(a) < 100 Ω
(b) < 4 Ω
(c) < 1 Ω
(d) > 2 Ω
► (c) < 1 Ω

5. A metallic conductor has loosely bound electrons called free electrons. The metallic
conductor is
(a) negatively charged
(b) positively charged
(c) neutral
(d) Either positively charged or negatively charged
► (c) neutral

6. Calculate the current flows through the 10 Ω resistor in the following circuit. (a) 1.2 A
(b) 0.6 A
(c) 0.2 A
(d) 2.0 A
► (b) 0.6 A

7. If R1 and R2 be the resistance of the filament of 40 W and 60 W respectively operating 220 V, then
(a) R1 < R2
(b) R2 < R1
(c) R1 = R2
(d) R1 ≥ R2
► (b) R2 < R1

8.  Resistivity of a metallic wise depends on
(a) its length
(b) its shape
(c) its thickness
(d) nature of material
►  (d) nature of material

9. A coil in the heater consume power P on passing current. If it is cut into halves and joined in parallel, it will consume power
(a) P
(b) P/2
(c) 2P
(d) 4P
► (d) 4P

10. Two resistors are connected in series gives an equivalent resistance of 10 Ω. When connected in parallel, gives 2.4 Ω. Then the individual resistance are
(a) each of 5 Ω
(b) 6 Ω and 4 Ω
(c) 7 Ω and 4 Ω
(d) 8 Ω and 2 Ω
► (b) 6 Ω and 4 Ω

11. If the current I through a resistor is increased by 100% the increased in power dissipation will be (assume temperature remain unchanged)
(a)100%
(b) 200%
(c) 300%
(d) 400%
► (c) 300%

12. The nature of the graph between potential difference and the electric current flowing through a conductor is
(a)parabolic
(b) circle
(c) straight line
(d) hyperbolic
► (c) straight line

13. A cooler of 1500 W, 200 volt and a fan of 500 W, 200 volt are to be used from a household supply. The rating of fuse to be used is
(a) 2.5 A
(b) 5.0 A
(c) 7.5 A
(d) 10 A
► (d) 10 A

14. The resistance of hot filament of the bulb is about 10 times the cold resistance. What will be the resistance of 100 W-220 V lamp, when not in use?
(a) 48 Ω
(b) 400 Ω
(c) 484 Ω
(d) 48.4 Ω
► (c) 484 Ω

15. A student says that the resistance of two wires of same length and same area of cross section is same. This statement is correct if
(a) Both wires are of different materials
(b) Both wires are made of same material and are at different temperature.
(c) Both wires are made of same material and are at same temperature.
(d) Both wires are made of different materials and are at the same temperature.
► (c) Both wires are made of same material and are at same temperature.

16. A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly
(a) 1020
(b) 1016
(c) 1018
(d) 1023
► (a) 1020

17. The effective resistance between A and B is (a) 4Ω
(b) 6Ω
(c) May be 10 Ω
(d) Must be 10 Ω
► (a) 4Ω

18. What is the maximum resistance which can be made using five resistors each of 1/5 W?
(a) 1/5 Ω
(b) 10 Ω
(c) 5 Ω
(d) 1 Ω
► (d) 1 Ω

19. Work done to move 1coulomb charge from one point to another point on a charged
conductor having potential 10volt is
(a) 1 Joule
(b) 10 Joule
(c) zero
(d) 100 Joule
► (c) zero

20. Electric potential is a:
(a) scalar quantity
(b) vector quantity
(c) neither scalar nor vector
(d) sometimes scalar and sometimes vector
► (a) scalar quantity

21. Coulomb is the SI unit of:
(a) charge
(b) current
(c) potential difference
(d) resistance
► (a) charge

22. A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio R/R’ is:
(a) 1/25
(b) 1/5
(c) 5
(d) 25
► (d) 25

23. The heating element of an electric iron is made up of:
(a) copper
(b) nichrome
(c) aluminium
(d) iron
► (b) nichrome

24. 1 mV is equal to:
(a) 10 volt
(b) 1000 volt
(c) 10-3 volt
(d) 10-6 volt
► (c) 10-3 volt

25. When electric current is passed, electrons move from:
(a) high potential to low potential.
(b) low potential to high potential.
(c) in the direction of the current.
(d) against the direction of the current.
► (b) low potential to high potential.

26. An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power
consumed will be:
(a) 100 W
(b) 75 W
(c) 50 W
(d) 25 W
► (d) 25 W

27. The electrical resistance of insulators is
(a) high
(b) low
(c) zero
(d) infinitely high
► (d) infinitely high

28. Electric power is inversely proportional to
(a) resistance
(b) voltage
(c) current
(d) temperature
► (a) resistance

29. An electric bulb is connected to a 220V generator. The current is 0.50 A. What is the power of the bulb?
(a) 440 W
(b) 110 W
(c) 55 W
(d) 0.0023 W
► (b) 110 W

30. Which of the following gases are filled in electric bulbs?
(a) Helium and Neon
(b) Neon and Argon
(c) Argon and Hydrogen
(d) Argon and Nitrogen
► (d) Argon and Nitrogen

31. The resistivity of insulators is of the order of
(a) 10-8-m
(b) 101-m
(c) 10-6-m
(d) 106-m
►(a) 10-8 Ω-m

32. Three resistors of 1 Ω, 2 ft and 3 Ω are connected in parallel. The combined resistance of the three resistors should be
(a) greater than 3 Ω
(b) less than 1 Ω
(c) equal to 2 Ω
(d) between 1 Ω and 3 Ω
► (b) less than 1 Ω

33. 100 J of heat is produced each second in a 4Ω resistor. The potential difference across the resistor will be:
(a) 30 V
(b) 10 V
(c) 20 V
(d) 25 V
► (b) 10 V

34. A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of
(a) more length
(c) less length

35. Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is
(a) current
(b) voltage
(c) resistance
(d) None of these
► (b) voltage

36. A boy records that 4000 joule of work is required to transfer 10 coulomb of charge between two points of a resistor of 50 Ω. The current passing through it is
(a) 2 A
(b) 4 A
(c) 8 A
(d) 16 A
► (c) 8 A

37. Electrical resistivity of any given metallic wire depends upon
(a) its thickness
(b) its shape
(c) nature of the material
(d) its length
► (c) nature of the material

38. What is the commercial unit of electrical energy?
(a) Joules
(b) Kilojoules
(c) Kilowatt-hour
(d) Watt-hour
► (c) Kilowatt-hour

39. Assertion: In an open circuit, the current passes from one terminal of the electric cell to another.
Reason: Generally, the metal disc of a cell acts as a positive terminal.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both A and R are false.
► (d) A is false but R is true.

40. Assertion: Bending of wire decrease the resistance of electric wire.
Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both A and R are false.
► (a) Both A and R are true and R is the correct explanation of A.

41. Assertion: When a battery is short circuited, the terminal voltage is zero.
Reason: In short circuit, the current is zero.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both A and R are false.
► (c) A is true but R is false.

42. Assertion: Conductors allow the current to flow through themselves.
Reason: They have free charge carriers.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both A and R are false.
► (a) Both A and R are true and R is the correct explanation of A.