Electrical CircuitsCopy
1. What is the SI unit of electrical charge?
A. Ampere
B. Coulomb
C. Volt
D. Ohm
2. Which statement about charges is correct?
A. Like charges attract and unlike charges repel
B. All charges attract each other
C. Like charges repel and unlike charges attract
D. Charges do not interact
3. What is observed when a plastic rod is rubbed with a cloth?
A. Positive charge flows from rod to cloth
B. Electrons are transferred between the materials
C. Protons move from rod to cloth
D. Charge is created in the rod
4. In charging by friction, what moves between the two objects?
A. Positive charge
B. Protons
C. Neutrons
D. Electrons
5. An electric field is defined as:
A. A region where light is refracted
B. A region where a magnetic material is attracted
C. A region where a charged object experiences a force
D. A space without any matter
6. The direction of an electric field line is defined by:
A. Direction of gravity
B. Direction of force on a negative charge
C. Direction of force on a positive charge
D. Direction of current flow
7. Which diagram best represents the field around a positive point charge?
A. Arrows pointing outward from the charge
B. Arrows pointing inward toward the charge
C. Circles around the charge
D. No arrows; only lines
8. What do electric field lines look like between two oppositely charged parallel plates?
A. Curved lines
B. Irregular patterns
C. Parallel straight lines
D. Circular lines
9. Which of the following is a good electrical conductor?
A. Rubber
B. Plastic
C. Wood
D. Copper
10. Which is a typical insulator?
A. Aluminium
B. Glass
C. Silver
D. Iron
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Physics Full Scale Course
11. What is the function of an experiment using a bulb, battery, and wires to test different materials?
A. To generate electricity
B. To distinguish between conductors and insulators
C. To test magnetic fields
D. To measure electric field strength
12. What makes a metal a good conductor of electricity?
A. High density
B. Free electrons
C. High resistance
D. Heavy nuclei
13. Which equation defines electric current?
A. I = V × R
B. I = Q / t
C. I = P × t
D. I = Q × t
14. Current in a wire is caused by:
A. Movement of neutrons
B. Flow of protons
C. Movement of electrons
D. Transfer of energy only
15. The SI unit of electric current is:
A. Volt
B. Ampere
C. Ohm
D. Coulomb
16. 1 ampere is equivalent to:
A. 1 coulomb per second
B. 1 volt per second
C. 1 joule per second
D. 1 ohm per coulomb
17. Which type of current changes direction periodically?
A. Direct current
B. Constant current
C. Alternating current
D. Static current
18. In a metal wire, current flows from:
A. Negative to positive
B. Positive to negative
C. Centre to edges
D. High to low resistance
19. Conventional current is taken to flow from:
A. Negative to positive
B. Positive to negative
C. Electron to ion
D. Anode to cathode only
20. Which device is used to measure electric current?
A. Voltmeter
B. Ammeter
C. Ohmmeter
D. Wattmeter
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Physics Full Scale Course
21. What is e.m.f.?
A. Energy lost per unit time
B. Energy required to move a unit charge through a resistor
C. Work done by a source per unit charge around a complete circuit
D. Voltage across a component
22. Which equation defines e.m.f.?
A. E = V / Q
B. E = W / Q
C. E = IR
D. E = Q × t
23. What is the unit of e.m.f.?
A. Ampere
B. Joule
C. Coulomb
D. Volt
24. A battery does 12 J of work to move 2 C of charge. What is its e.m.f.?
A. 6 V
B. 12 V
C. 0.17 V
D. 24 V
25. Potential difference is defined as:
A. Work done on a component per unit charge
B. Charge per unit work
C. Resistance per unit current
D. Power divided by time
26. What is the relationship between e.m.f. and p.d.?
A. e.m.f. and p.d. are always equal
B. e.m.f. is greater than p.d. in a real circuit
C. p.d. is always greater than e.m.f.
D. There is no relation
27. Volt is defined as:
A. 1 joule per coulomb
B. 1 ampere per second
C. 1 ohm per ampere
D. 1 coulomb per joule
28. Which instrument is used to measure p.d.?
A. Ammeter
B. Ohmmeter
C. Voltmeter
D. Thermometer
29. What is the total e.m.f. in series combination of 3 cells of 2 V each?
A. 2 V
B. 3 V
C. 6 V
D. 12 V
30. What is the total e.m.f. in parallel combination of 3 identical 2 V cells?
A. 2 V
B. 6 V
C. 1.5 V
D. 4 V
31. What is the formula for resistance?
A. R = V / I
B. R = I / V
C. R = V × I
D. R = Q / t
32. An experiment to determine resistance involves:
A. A voltmeter and a stopwatch
B. A thermometer and a voltmeter
C. An ammeter and a voltmeter
D. A voltmeter and a spring balance
33. Resistance of a wire increases with:
A. Decreasing length
B. Increasing cross-sectional area
C. Increasing temperature
D. Use of superconductors
34. Resistance is directly proportional to:
A. Current
B. Length
C. Temperature
D. Charge
35. Resistance is inversely proportional to:
A. Current
B. Length
C. Cross-sectional area
D. Voltage
36. Ohm’s Law states that:
A. Current is directly proportional to voltage at constant resistance
B. Voltage is inversely proportional to resistance at constant current
C. Resistance increases with voltage
D. Resistance is constant for all materials
37. A filament lamp behaves differently from a resistor because:
A. Its resistance remains constant
B. Its resistance decreases with temperature
C. Its resistance increases with temperature
D. It has no resistance
38. What does the I–V graph of an ohmic resistor look like?
A. Curved line
B. Straight line through origin
C. Horizontal line
D. Parabolic curve
39. What does the I–V graph of a filament lamp look like?
A. Straight line
B. Curved line flattening at high V
C. Horizontal line
D. Vertical line
40. What is the effect of temperature increase on the resistance of a filament lamp?
A. Resistance decreases
B. Resistance increases
C. No change
D. Resistance drops to zero
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Physics Full Scale Course
Answer key and explanations
1. Correct Answer: B
Explanation: Charge is measured in coulombs (C)
2. Correct Answer: C
Explanation: Like charges repel, unlike charges attract
3. Correct Answer: B
Explanation: Friction causes electrons to transfer between materials, producing static charge
4. Correct Answer: D
Explanation: Only electrons (negative charges) move during frictional charging
5. Correct Answer: C
Explanation: Electric field is a region where a charge experiences force
6. Correct Answer: C
Explanation: Electric field direction is defined by the force on a positive test charge
7. Correct Answer: A
Explanation: Electric field lines radiate outward from a positive point charge
8. Correct Answer: C
Explanation: The field between parallel plates is uniform and made of straight parallel lines
9. Correct Answer: D
Explanation: Copper is a good conductor due to free electrons
10. Correct Answer: B
Explanation: Glass is a poor conductor and is considered an insulator
11. Correct Answer: B
Explanation: If the bulb lights up, the material conducts electricity → distinguishing conductor/insulator
12. Correct Answer: B
Explanation: Metals conduct electricity due to free-moving (delocalised) electrons
13. Correct Answer: B
Explanation: I = Q / t defines current as charge per unit time
14. Correct Answer: C
Explanation: Electrons, being negatively charged, flow and constitute current in metals
15. Correct Answer: B
Explanation: Ampere (A) is the SI unit of current
16. Correct Answer: A
Explanation: 1 A = 1 C/s
17. Correct Answer: C
Explanation: Alternating current (a.c.) reverses direction periodically
18. Correct Answer: A
Explanation: Electron flow is from negative to positive
19. Correct Answer: B
Explanation: Conventional current assumes flow from + to –
20. Correct Answer: B
Explanation: Ammeter measures current in a circuit
21. Correct Answer: C
Explanation: e.m.f. = work done per unit charge around the entire circuit
22. Correct Answer: B
Explanation: E = W / Q is the correct formula for e.m.f.
23. Correct Answer: D
Explanation: e.m.f. and potential difference are measured in volts
24. Correct Answer: A
Explanation: E = W/Q = 12 / 2 = 6 V
25. Correct Answer: A
Explanation: p.d. = energy used by a component per unit charge
26. Correct Answer: B
Explanation: Due to internal resistance, e.m.f. > p.d. in real circuits
27. Correct Answer: A
Explanation: Volt = joule/coulomb (V = J/C)
28. Correct Answer: C
Explanation: Voltmeter measures p.d.
29. Correct Answer: C
Explanation: In series, total e.m.f. = sum = 2 + 2 + 2 = 6 V
30. Correct Answer: A
Explanation: In parallel, total e.m.f. = e.m.f. of one source = 2 V
31. Correct Answer: A
Explanation: R = V / I defines resistance as p.d. per unit current
32. Correct Answer: C
Explanation: To find resistance, measure current (ammeter) and voltage (voltmeter)
33. Correct Answer: C
Explanation: Higher temperature = more resistance due to increased lattice vibrations
34. Correct Answer: B
Explanation: R ∝ length for a uniform wire
35. Correct Answer: C
Explanation: R ∝ 1/area
36. Correct Answer: A
Explanation: Ohm’s law: V ∝ I if temperature is constant
37. Correct Answer: C
Explanation: Filament lamp’s resistance increases as it heats up
38. Correct Answer: B
Explanation: Ohmic resistors have a linear I–V graph through the origin
39. Correct Answer: B
Explanation: Filament lamp graph curves and flattens due to rising resistance
40. Correct Answer: B
Explanation: Heating causes more resistance in filament → less current at high voltage