Class 10 Science MCQ Chapter 12 Electricity, Class 10 Science MCQ Question Answer, Class 10 Science Multiple Choice Question Answer to each chapter is provided in the list of SCERT Science Class 10 Objective Types Question Answer so that you can easily browse through different chapters and select needs one. Class 10 Science MCQ Chapter 12 Electricity Question Answer can be of great value to excel in the examination.
SCERT Class 10 Science MCQ Chapter 12 Electricity
SCERT Class 10 General Science MCQ Chapter 12 Electricity Notes covers all the exercise questions in SCERT Science Textbooks. The NCERT Class 10 Science MCQ Chapter 12 Electricity provided here ensures a smooth and easy understanding of all the concepts. Understand the concepts behind every chapter and score well in the board exams.
Electricity
Chapter – 12
Multiple Choice Questions & Answers
1. SI unit of electric charge –
(a) Ampere.
(b) Volt.
(c) Coulomb.
(d) Watt.
Ans: (c) Coulomb.
2. Number of electrons constituting 1 coulomb of charge-
(a) 6.25 x 10¹⁹
(b) 6.25 x 10²⁰
(c) 6.25 x 10¹²
(d) 6.25 x 10¹⁸
Ans: (d) 6.25 x 10¹⁸
3. SI unit of electric current-
(a) Volt.
(b) Watt.
(c) Coulomb.
(d) Ampere.
Ans: (d) Ampere.
4. Amount of charge present in an electron-
(a) 1.6 × 10 ⁻¹⁹C
(b) 1.6 × 10 ⁻¹⁸C
(c) 1.6 x 10⁻¹¹C
(d) 1.6 x 10⁻⁶C
Ans: (a) 1.6 × 10 ⁻¹⁹C
5. Which one of the following statements is incorrect for an electric circuit-
(a) Direction of current is from the positive terminal of the electric cell to the negative terminal.
(b) Direction of flow of electrons is same as the direction of current.
(c) Direction of flow of electrons is opposite to the direction of current.
(d) Direction of flow of positive charge is taken to be the direction of current.
Ans: (b) Direction of flow of electrons is same as the direction of current.
6. Which one of the following expressions represents 1 Ampere-
(a) IC/IV
(b) IV/ IC
(c) IC/IS
(d) IJ/ IC
Ans: (c) IC/IS
7. The instrument which measures the magnitude of current in an electric circuit is-
(a) Voltmeter.
(b) Ammeter.
(c) Galvanometer.
(d) Variable resistance.
Ans: (b) Ammeter.
8. If the filament of an electric bulb draws 0.5A current in 20 minutes, then the amount of electric charge passing through the circuit will be –
(a) 5C
(b) 50C
(c) 600C
(d) 300C
Ans: (c) 600C
9. How many electrons should flow in 1s to constitute 1 µ A of cur-
(a) 1.6 × 10 ¹⁵
(b) 1.6 × 10 ¹⁹
(c) 1.6 x 10 ¹²
(d) 1.6 x 10 ⁶
Ans: (c) 1.6 x 10 ¹²
10. Which of the following expressions represents 1 volt –
(a) 1JC ⁻¹
(b) 1Cs ⁻¹
(c) 1Js ⁻¹
(d) 1VC ⁻¹
Ans: (a) 1JC ⁻¹
11. The instrument that is used to measure the potential difference across two points in an electric circuit-
(a) Ammeter.
(b) Voltmeter.
(c) Galvanometer.
(d) Variable resistance.
Ans: (b) Voltmeter.
12. A voltmeter is connected between the two points across which potential difference is to be measured –
(a) In parallel.
(b) In series.
(c) Either in series or in parallel.
(d) None of these.
Ans: (a) In parallel.
13. An ammeter is connected in a circuit to measure the current of the circuit –
(a) In parallel.
(b) In series.
(c) Either in series or in parallel.
(d) None of these.
Ans: (b) In series.
14. Amount of work that is done in moving a charge of 4C across two points having a potential difference of 6 V-
(a) 1.5 J
(b) 12 J
(c) 2/3
(d) 24 J
Ans: (d) 24 J
15. The resistance of a resistor drawing 2mA of current when the potential difference across its two ends is 9V is-
(a) 2Ω
(b) 4Ω
(c) 4.8 × 10³Ω
(d) 4.8Ω
Ans: (c) 4.8×10³Ω
16. When 3 μ A current flows through a resistor of resistance 20Ω, then the potential difference across the resistor is-
(a) 60V
(c) 6 × 10⁻⁷V
(b) 10V
(d) 6 x 10⁻⁵ V
Ans: (d) 6 x 10⁻⁵ V
17. The current drawn by an electric iron having resistance 15 Ω when operated at a potential difference of 3kV is –
(a) 200A
(b) 45A
(c) 45000A
(d) 5A
Ans: (a) 200A
18. SI unit of electrical resistance is –
(a) Ω
(b) Ω m
(c) C
(d) A
Ans: (a) Ω
19. Which one of the following represents 1 Ohm?
(a) 1V/1s
(b) 1V/1A
(c) 1J/1C
(d) 1C/1s
Ans: (b) 1V/1A
20. The electrical device that regulates current changing the voltage source is –
(a) Galvanometer.
(b) Ammeter.
(c) Voltmeter.
(d) Variable resistance (Rheostat ).
Ans: (d) Variable resistance (Rheostat ).
21. The factor on which resistance of a conductor depends –
(a) Length of the con-ductor.
(b) Area of cross-section of the conductor.
(c) Temperature of the conductor.
(d) All of the above.
Ans: (d) All of the above.
22. The conducting wire of a circuit is made double by its length. The current in the circuit will-
(a) Increase by twice.
(b) Decrease to half.
(c) 1/2 of the former value.
(d) Remain same.
Ans: (b) Decrease to half.
23. Keeping the potential difference constant if the resistance of an electrical component is reduced to half, the current through it will be-
(a) Half.
(b) The same.
(c) Double.
(d) 4 times.
Ans: (c) Double.
24. Keeping the resistance of an electrical component constant, if the potential difference across the two ends of it is reduced to half, the current through it will be –
(a) Twice.
(b) 3 times.
(c) 4 times.
(d) Half.
Ans: (d) Half.
25. SI unit of resistivity of a material is –
(a) Ω
(b) Ω m
(c) Ω m⁻¹
(d) Ω m⁻²
Ans: (b) Ω m
26. A wire of resistance 2Ω is divided into four equal parts. The pieces are arranged in parallel. If the equivalent resistance of the parallel combination is represented by R, then 2Ω : R will be.
(a) 16
(b) 1/4
(c) 1/8
(d) 8
Ans: (a)16
27. The ratio of lengths, resistances and resistivities of two wires is 1:2 in each case. What will be ratio of the diameters of the two wires?
(a) 1: 2
(b) 1: 4
(c) 4 :1
(d) 1: √2
Ans: (d) 1: √2
28. Which of the following statements is incorrect for series combination of resistors?
(a) Current through each resistor is same.
(b) The potential difference across each resistor is same as the total potential difference of the circuit.
(c) Total resistance of the circuit increases heavily.
(d) Total current of the circuit decreases heavily.
Ans: (b) The potential difference across each resistor is same as the total potential difference of the circuit.
29. Which one of the following statements is incorrect for the parallel combination of resistors?
(a) Total current of the circuit increases.
(b) Total resistance of the circuit decreases.
(c) Equal amount of current flows through each resistor, which is equal to the total current of the circuit.
(d) Potential difference across each resistor is same and is equal to the total potential difference of the circuit.
Ans: (c) Equal amount of current flows through each resistor, which is equal to the total current of the circuit.
30. The total resistance of the combination given in the following figure-
(a) 5Ω
(b) 2Ω
(c) 6Ω
(d) 21Ω
Ans: (b) 2Ω
31. The equivalent resistance of the combination given in the following figure-
(a) 5Ω
(b) 2.5Ω
(c) 10Ω
(d) 1Ω
Ans: (b) 2.5Ω
32. Which one of the following equations represents the Joule’s law of heating –
(a) P = VI
(b) V = IR
(c) H = I²Rt
(d) P = V ²/R
Ans: (c) H = I²Rt
33. Which one of the following devices does not work on the principle of heating effect of electric current?
(a) Electric iron.
(b) Electric fan.
(c) Toaster.
(d) Electric Kettle.
Ans: (b) Electric fan.
34. The rate of consumption of energy in an electric circuit is called –
(a) Electric current.
(b) Electrical resistance.
(c) Electrical potential difference.
(d) Electric power.
Ans: (d) Electric power.
35. SI unit of electrical power is-
(a) Ohm.
(b) Volt.
(c) Watt.
(d) Ampere.
Ans: (c) Watt.
36. Which of the following expressions represents electrical power-
(a) E/t
(b) Q/t
(c) W/Q
(d) V/R
Ans: (a) E/t
37. Which of the following expressions represent 1 watt-
(a) 1V × 1C
(b) 1V × 1A
(c) 1A × 1Ω
(d) 1J/1C
Ans: 1V × 1A
38. Which one of the following is the commercial unit of energy-
(a) Joule.
(b) Kilowatt.
(c) Kilowatt hour.
(d) Watt.
Ans: (c) Kilowatt hour.
39. The commercial unit of electrical energy 1 kwh represents
(a) 36 × 10 ⁶J
(b) 3.6 × 10⁶J
(c) 3.6 × 10⁵J
(d) 36 × 10 ⁴J
Ans: (b) 3.6 × 10⁶ J
40. Which of the following metals is used for filaments exclusively in electric bulbs?
(a) Copper.
(b) Aluminium.
(c) Nickel.
(d) Tungsten.
Ans: (d) Tungsten.
41. On which of the following effects does an electrical fuse work?
(a) Magnetic effect of electric current.
(b) Light effect of electric current.
(c) Heating effect of electric current.
(d) Mechanical effect of electric current.
Ans: (c) Heating effect of electric current.
42. Which of the following is used to make coils of electrical heating devices?
(a) Copper.
(b) Nickel.
(c) Tungsten.
(d) Nichrome.
Ans: (d) Nichrome.
43. 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 combi-nation is R’, then the ratio R/R’ is-
(a) 1/25
(b) 1\5
(c) 5
(d) 25
Ansl: (d) 25
44. Which of the following terms does not represent electrical power in a circuit?
(a) I²R
(b) IR²
(e) VI
(d) V²/ A
Ans: (b) IR²
45. An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be-
(a) 100W
(b) 75W
(c) 50W
(d) 25W
And: (d) 25W
46. Two conducting wires of the same material and of equal lengths and equal di-ameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be-
(a) 1: 2
(b) 2 : 1
(c) 1 : 4
(d) 4 :1
Ans: (c) 1: 4
Very Short & Short Type Questions and Answers:
1. What is electric current?
Ans: The amount of electric charge passing through a cross-section of a conductor in unit time is called electric current.
2. What is the SI unit of electric charge?
Ans: Coulomb (C).
3. What is the SI unit of electric current?
Ans: Ampere (A).
4. Define 1 Ampere of current.
Ans: When 1 coulomb of charge passes through a cross-section of conductor in 1 second, then the amount of electric current passing through the cross-section is said to be 1 Ampere.
5. How many electrons constitute 1 coulomb of charge?
Ans: 6.25 × 10¹⁸
6. What is the conventional direction of electric current?
Ans: From the positive terminal to the negative terminal of an electric cell or battery in an electric circuit.
7. What is the direction of flow of electrons in an electric circuit?
Ans: From the negative terminal (region of lower potential) to the positive terminal (region of higher potential) of an electric cell or battery.
8. What is the necessary condition for the flow of charge in a conductor?
Ans: Establishing a potential difference across the two ends of the conductor.
9. What is an ammeter?
Ans: It is an instrument which measures the amount of electric current in an electric circuit.
10. How is an ammeter connected in an electric circuit?
Ans: In series with the components of the circuit.
11. What do you mean by electric potential difference?
Ans: The amount of work to be done to bring a unit positive charge from one point to another within an electric field is said to be the electric potential difference between the two points.
12. What is the SI unit of electric potential difference?
Ans: Volt (V).
13. Define 1 Volt of potential difference?
Ans: If 1 joule of work is done in moving 1 coulomb of charge from one point to another within an electric field, then the potential difference between the two
points is said to be 1 volt 1V =1J/ 1C
14. What is a voltmeter?
Ans: It is an instrument which measures potential difference across two points in an electric circuit.
15. Write the Ohm’s law.
Ans: The potential difference across the two ends of a metallic wire connected in an electric circuit is proportional to the electric current through it, provided the temperature remains constant. This is known as Ohm’s law.
16. Write the mathematical expression for Ohm’s law.
Ans: If V is the potential difference across the two ends of a conductor and I is the current through it, then
V ∝ I
⇒ V/I =R [ Where R is a constant.]
⇒ V = IR
Here, R = Resistance of the conductor.]
17. Draw graph for a nichrome wire.
Ans:
18. What is resistance of a conductor?
Ans: It is a property of a conductor by virtue of which it resists the flow of charge through it.
19. What is the SI unit of resistance?
Ans: Ohm Ω.
20. Define 1Ω of resistance.
Ans: If 1A current passes through a conductor having IV of difference across its two ends, then the resistance of the conductor is said to be 1Ω.
[1Ω = 1V /1A]
21. What is a variable resistance (Rheostat)?
Ans: The component is an electric circuit which regulates the current with out changing the voltage source is called a variable resistance or rheostat.
22. How does resistance of a conductor depend on its length?
Ans: Resistance of a conductor is proportional to its length [R∝ι].
23. Between a long wire and a short wire made of the same metal and of equal area of cross-section, through which will current flow more easily?
Ans: Through the short wire, as the long wire will have more resistance.
24. How does the resistance of a conductor depend on the area of cross-section of it?
Ans: Resistance of a conductor is inversely proportional to its area of cross-section
[R∝ 1/R].
25. What does the resistivity of a substance mean?
Ans: The resistivity of a substance is the resistance of a wire made of that substance having length of 1m and area of cross-section of 1m².
26. What do you mean by the heating effect of electric current?
Ans: For a purely resistive circuit, i.e. a configuration of resistors is only connected to the battery, the entire source energy is dissipated in the form of heat. This is called the heating effect of electric current.
27. State the Joule’s law of heating.
Ans: The heat generated by a resistor of resistance R in time t when a steady current I flows through it is given by an equation – H = 1²Rt. This is known as Joule’s law of heating.
28. How is the life of the filament of an electric bulb prolonged?
Ans: By inserting chemically inert gas like argon and nitrogen in the bulbs.
29. What is an electric fuse?
Ans: It is a safety device used in domestic electric circuits which protects the circuit and electrical devices by stopping unduly high current.
30. What is the principle of electric fuse?
Ans: It is based on the heating effect of electric current.
31. What is electric power?
Ans: It is the rate of consumption of energy in an electric circuit.
32. What is the SI unit of electrical power?
Ans: Watt (W).
33. Define 1 watt of power.
Ans: The power consumed by an electric device carrying 1A of current when operated at 1V of potential difference is called 1 Watt. [1W = 1V× 1A].
34. What is the commercial unit of electrical energy?
Ans: Kilowatt hour (kWh).
35. Draw a circuit diagram connecting a 2V battery, a 10Ω resistor, a plug key, an ammeter to measure current and voltmeter to measure potential difference across the 10Ω resistor.
Ans:
36. What will be the relationship between the current through three resistors connected in parallel if the relationship between their resistances is R₁>R₂>R₃.
Ans: l₁<l₂<l₃
37. What is the principle of electrical devices like electric iron, electric heater, toaster etc?
Ans: Heating effect of electric current.
38. What is the principle behind the production of light by an electric bulb with a filament?
Ans: Heating effect of electric current.
39. Write the name and symbol of the metal that is used to make filament of electric bulbs.
Ans: Tungsten (W).
40. Keeping potential difference same, if resistance of an electric circuit is doubled, how will the current in the circuit change?
Ans: Current will be half of the previous value, as I∝ 1/R
41. How do resistance and resistivity of materials charge with temperature?
Ans: Resistance and resistivity both increases with temperature.
42. Define 1 kilowatt hour of energy.]
Ans: The energy consumed by an electric device of power 1kW when used for 1h is called 1 kilowatt hour.
43. Draw a circuit diagram to show three resistors of resistance R₁,R₂ and R₃ connected in series with a battery, through an ammeter and a plug key. Also show a voltmeter to measure the potential difference across the ends of the combination of the resistors.
Ans:
44. Draw a circuit diagram to show a parallel combination of three resistors having resistances R₁,R₂ and R₃ connected with a battery through an ammeter and a plug key. Also show a voltmeter to measure the potential difference the combination of resistors.
Ans:
