Electricity

Physics, SSC-Punjab Class 10. This chapter is split into 61 topics and has 1,506 practice questions. The topics covered are listed below, followed by 10 free sample questions from the chapter.

Topics in this chapter

1. Potential Divider with LDR and Thermistor 20 questions
2. Joule Law and Heating Effect 23 questions
3. Joule Heating H equals I squared R t 30 questions
4. Earth Wire and Double Insulation 20 questions
5. Current Voltage Data and Ohmic Behaviour 21 questions
6. Resistors in Series and Parallel Concepts 24 questions
7. Electric Current and its Unit 23 questions
8. Live Neutral and Earth Wires 20 questions
9. Electromotive Force 23 questions
10. Resistance from Resistivity Length and Area 26 questions
11. Current from Charge and Time 30 questions
12. Electric Power Concepts 22 questions
13. EMF versus Potential Difference 21 questions
14. Conduction by Free Electrons in Metals 22 questions
15. Comprehensive Review of Electricity 25 questions
16. Cost of Electricity Bills 30 questions
17. Ohm Law Finding Potential Difference 30 questions
18. Light Dependent Resistor 22 questions
19. NTC Thermistor 22 questions
20. Combining Cells in Series and Parallel 30 questions
21. Decoding Resistor Colour Bands 25 questions
22. Potential Divider Concepts 20 questions
23. Kilowatt-hour Energy Calculations 30 questions
24. Direct and Alternating Current 23 questions
25. Energy and Charge from Voltage 25 questions
26. Fuses and Trip Switches 22 questions
27. Household Circuits in Parallel 21 questions
28. Potential Difference from Work and Charge 30 questions
29. Series and Parallel Combinations Mixed Circuits 22 questions
30. Conventional and Electronic Current 23 questions
31. Electrical Hazards 21 questions
32. Resistor Colour Codes 24 questions
33. Potential Difference and Voltage 24 questions
34. Circuit Symbols and Components 23 questions
35. Alternating Current Frequency and Period 28 questions
36. Two Resistors in Parallel 26 questions
37. Series Circuit Current and Voltage Drops 23 questions
38. Resistance Changes with Length and Area 29 questions
39. Power from I squared R and V squared over R 30 questions
40. Electron Flow and Current Calculations 26 questions
41. Fuse Ratings and Household Appliance Currents 30 questions
42. Cells in Series and Parallel Concepts 23 questions
43. Exercise Style Short and Constructed Response on Electricity 22 questions
44. Electric Power from Current and Voltage 24 questions
45. Equal Resistors in Series and in Parallel 25 questions
46. Common Uses of Electricity 22 questions
47. Electrical Energy E equals IVt 27 questions
48. Potential Divider Calculations 27 questions
49. Resistors in Series Equivalent Resistance 30 questions
50. Electrical Resistivity 24 questions
51. Finding Resistivity Length or Area 26 questions
52. Colour Code Tolerance and Encoding 27 questions
53. Ammeter Use and Ranges 23 questions
54. Charge and Time from Current 27 questions
55. Voltmeter Use and Ranges 22 questions
56. Exercise Style Multiple Choice on Electricity 26 questions
57. Three Resistors in Parallel and Branch Currents 23 questions
58. Ohm Law Finding Current and Resistance 29 questions
59. Ohm Law and Resistance 24 questions
60. Kilowatt-hour and Electricity Bills 23 questions
61. Effect of Temperature on Resistance 23 questions

Sample questions: Electricity

10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.

Q1. In the circuit with a battery, in which direction do electrons move in the external wire?

• A. Backwards and forwards without drifting
• B. From the negative terminal to the positive(correct answer)
• C. Only through the battery itself
• D. From the positive terminal to the negative

Answer: B.Electrons are repelled by the negative terminal and attracted to the positive, so they flow negative to positive.

Q2. Why does current appear in a circuit almost immediately when the switch is closed even though electrons drift slowly?

• A. The field acts on all free electrons together(correct answer)
• B. The battery sends electrons at the speed of light
• C. One electron travels the whole circuit instantly
• D. The wire emits new electrons at the switch

Answer: A.The electric field spreads quickly through the wire and moves all the free electrons at once (standard knowledge).

Q3. The movement of electrons in one direction corresponds to the movement of positive charges in the

• A. opposite direction(correct answer)
• B. direction of the earth wire
• C. same direction
• D. direction of the magnetic field

Answer: A.The book states that electron movement in one direction is equivalent to positive charge in the opposite direction.

Q4. Which statement correctly defines e.m.f.?

• A. Energy used by a component per unit charge
• B. Energy supplied by a source to unit charge in a closed circuit(correct answer)
• C. Opposition offered by a wire to current
• D. Charge passing per unit time through a wire

Answer: B.E.m.f. is the electric potential energy supplied by the battery to a unit positive charge around the closed circuit.

Q5. What should be true of the resistance of an ideal voltmeter?

• A. Very high(correct answer)
• B. Zero
• C. Equal to the lamp
• D. Very low

Answer: A.A very high-resistance meter draws almost no current, so it does not disturb the circuit (as the exercise states).

Q6. Which wire of the mains supply is normally at about earth potential?

• A. The fuse wire
• B. The live wire
• C. The switch wire
• D. The neutral wire(correct answer)

Answer: D.The neutral wire returns current at about earth potential, so it is the safer of the two supply wires (standard knowledge).

Q7. Which components are listed in the learning outcomes for circuit diagrams?

• A. Cells, switches, resistors, thermistors, LDRs, lamps(correct answer)
• B. Springs, gears, pulleys
• C. Magnets, compasses, rods
• D. Mirrors, lenses, prisms

Answer: A.The SLO lists cells, batteries, switches, resistors, thermistors, LDRs, lamps, motors, meters, transformers, fuses, relays, diodes and LEDs.

Q8. The readings for a filament lamp are V = 1, 2, 3, 4 V and I = 0.2, 0.3, 0.36, 0.4 A. Which statement is correct?

• A. Resistance rises from 5 Ω to 10 Ω as the filament gets hotter, so the lamp is non-ohmic(correct answer)
• B. Resistance stays constant at 5 Ω, so the lamp obeys Ohm's law at all voltages shown
• C. Resistance equals the gradient of the I against V graph at all points, which is the same everywhere
• D. Resistance falls from 10 Ω to 5 Ω as the filament gets hotter, so the lamp is non-ohmic

Answer: A.V/I = 5 Ω at the first reading and 10 Ω at the last; the I against V graph curves because the hot metal filament resists more.

Q9. The readings for a filament lamp are V = 2, 4, 6, 8 V and I = 0.5, 0.8, 1, 1.1 A. Which statement is correct?

• A. Resistance stays constant at 4 Ω, so the lamp obeys Ohm's law at all voltages shown
• B. Resistance equals the gradient of the I against V graph at all points, which is the same everywhere
• C. Resistance rises from 4 Ω to 7.27 Ω as the filament gets hotter, so the lamp is non-ohmic(correct answer)
• D. Resistance falls from 7.27 Ω to 4 Ω as the filament gets hotter, so the lamp is non-ohmic

Answer: C.V/I = 4 Ω at the first reading and 7.27 Ω at the last; the I against V graph curves because the hot metal filament resists more.

Q10. The readings for a filament lamp are V = 1, 3, 5, 6 V and I = 0.25, 0.5, 0.65, 0.7 A. Which statement is correct?

• A. Resistance rises from 4 Ω to 8.57 Ω as the filament gets hotter, so the lamp is non-ohmic(correct answer)
• B. Resistance equals the gradient of the I against V graph at all points, which is the same everywhere
• C. Resistance falls from 8.57 Ω to 4 Ω as the filament gets hotter, so the lamp is non-ohmic
• D. Resistance stays constant at 4 Ω, so the lamp obeys Ohm's law at all voltages shown

Answer: A.V/I = 4 Ω at the first reading and 8.57 Ω at the last; the I against V graph curves because the hot metal filament resists more.