Multiple Choice Questions Bank
1. What is the SI unit of electric current?
0 a) Coulomb (C)
b) Ampere (A)
c) Volt (V)
d) Ohm (Ω)
2. What does conventional current refer to?
a) Flow of electrons
b) Flow of protons
c) Flow from positive to negative potential
d) Flow from negative to positive potential
3. What is the formula for potential difference?
a) V = IR
b) V = I/R
c) V = I + R
d) V = I - R
4. According to Ohm's Law, what is the relationship between voltage, current, and resistance?
a) V = I × R
b) V = I/R
c) V = R/I
d) V = I + R
5. Which component is used to measure electric current?
a) Voltmeter
b) Ammeter
c) Ohmmeter
d) Wattmeter
6. What type of current flows in one direction only?
a) Alternating Current (AC)
b) Direct Current (DC)
c) Pulsating Current
d) Static Current
7. Which of the following is a use of Direct Current (DC)?
a) Household appliances
b) Electric vehicles
c) Power transmission over long distances
d) Radio broadcasting
8. What is the primary voltage used in domestic supply in Pakistan?
a) 110 V
b) 220 V
c) 240 V
d) 50 V
9. Which instrument measures potential difference?
a) Ammeter
b) Voltmeter
c) Multimeter
d) Galvanometer
10. What is the danger associated with electricity?
a) It can cause burns.
b) It can cause explosions.
c) It can lead to electrocution.
d) All of the above.
11. Which of the following precautions should be taken when using electrical appliances?
a) Use wet hands while operating.
b) Ensure proper insulation of wires.
c) Overload circuits intentionally.
d) Ignore damaged plugs and wires.
12. What type of meter provides continuous readings?
a) Digital meter
b) Analogue meter
c) Smart meter
d) None of the above
13. The flow of electric charge is measured in:
a) Joules
b) Amperes
c) Volts
d) Ohms
14. If the resistance in a circuit increases, what happens to the current if voltage remains constant?
a) Current increases
b) Current decreases
c) Current remains unchanged
d) Current fluctuates
15. Which type of current alternates direction periodically?
a) Direct Current (DC)
b) Static Current
c) Alternating Current (AC)
d) Pulsating Current
16. What is the main advantage of AC over DC for power distribution?
a) Easier to generate
b) Can be transformed to higher voltages
c) More efficient for short distances
d) Safer for household use
17. What device converts AC to DC?
a) Transformer
b) Rectifier
c) Inverter
d) Capacitor
18. The term 'grounding' in electrical systems refers to:
a) Connecting to water supply
b) Connecting to earth for safety
c) Connecting all wires together
d) None of the above
19. What happens if you connect an appliance rated for 220V to a 110V supply?
a) It will operate normally
b) It will operate at half power
c) It will burn out
d) It will explode
20. Which material is commonly used as an insulator?
a) Copper
b) Aluminum
c) Rubber
d) Steel
21. How does increasing the voltage affect the current in an electrical circuit with constant resistance?
a) Increases current
b) Decreases current
c) No effect on current
d) Fluctuates current
22. The resistance of a conductor depends on:
a ) Length and cross-sectional area only
b ) Voltage and current only
c ) Temperature and material only
d ) All of the above
23. In which circuit configuration does voltage remain constant across all components?
a ) Series circuit
b ) Parallel circuit
c ) Open circuit
d ) Short circuit
24. If two resistors are connected in series, their total resistance is:
a ) Less than either resistor
b ) Equal to one resistor
c ) The sum of both resistances
d ) The product of both resistances
25. The power consumed by an electrical device can be calculated using which formula?
a ) P = IV
b ) P = I/R
c ) P = VR^2
d ) P = R/I
26. What happens when an electrical circuit is open?
a ) Current flows continuously
b ) Current stops flowing
c ) Voltage increases
d ) Resistance decreases
27. The unit of electrical power is:
a ) Joule
b ) Watt
c ) Volt
d ) Ampere
28. A fuse protects electrical circuits by:
a ) Increasing voltage
b ) Decreasing resistance
c ) Breaking the circuit when too much current flows
d ) Storing energy
29. Which component stores electrical energy in an electric field?
a ) Resistor
b ) Capacitor
c ) Inductor
d ) Diode
30. The heating effect of electric current is primarily due to:
a ) Magnetic fields
b ) Resistance in conductors
c ) Capacitance
d ) Induction
31. In an AC circuit, what does RMS stand for?
a ) Root Mean Square
b ) Random Mean Square
c ) Real Mean Square
d ) Relative Mean Square
32. Which device converts electrical energy into mechanical energy?
a ) Generator
b ) Motor
c ) Transformer
d ) Capacitor
33. A voltmeter should be connected in:
a ) Series
b ) Parallel
c ) Either series or parallel
d ) None of the above
34. When measuring voltage, which terminal should be connected to the positive side?
a ) Negative terminal
b ) Ground terminal
c ) Positive terminal
d ) Neutral terminal
35. If an appliance uses 1000 watts at 220 volts, what is its current draw?
a ) 4.5 A
b ) 5 A
c ) 6 A
d ) 7 A
36. The primary purpose of grounding in electrical systems is to:
a ) Improve efficiency
b ) Provide safety against shocks
c ) Enhance performance
d ) Reduce costs
37. An electric charge can be:
a ) Positive only
b ) Negative only
c ) Both positive and negative
d ) Neither
38. What type of circuit allows multiple paths for current flow?
a ) Series circuit
b ) Parallel circuit
c ) Open circuit
d ) Closed circuit
39. Which statement about insulators is true?
a.) They allow electric charge to flow easily
b.) They do not allow electric charge to flow
c.) They are always made from metals
d.) They are always good conductors
40. The total charge passing through any point in an electric circuit per second is called:
a.) Voltage
b.) Current
c.) Resistance
d.) Power
41. In which type of meter can you read values directly without calculations?
a.) Digital meter
b.) Analogue meter
c.) Both
d.) None
42. When two identical resistors are connected in parallel, their equivalent resistance is:
a.) Greater than either resistor
b.) Less than either resistor
c.) Equal to one resistor
d.) Twice that of one resistor
43. The primary function of an ammeter is to measure:
a.) Voltage
b.) Power
c.) Resistance
d.) Current
44. What does the term 'short circuit' refer to?
a.) A complete path for current flow
b.) A break in the circuit
c.) An unintended low-resistance connection
d.) A high-resistance connection
45. Which characteristic distinguishes AC from DC?
a.) Directional flow
b.) Frequency
c.) Voltage level
d.) Resistance
46. In terms of safety, what should you do before working on electrical devices?
a.) Wear rubber gloves
b.) Ensure devices are unplugged
c.) Use metal tools
d.) None of these
47. What does 'electromotive force' (emf), often referred to as voltage, indicate?
a.) The energy per unit charge
b.) The total charge in motion
c.) The resistance offered by materials
d.) The power consumed by devices
Answers:
1-b, 2-c, 3-a, 4-a, 5-b, 6-b, 7-b, 8-b, 9-b, 10-d,
11-b, 12-a, 13-b, 14-b, 15-c, 16-b, 17-b, 18-b,
19-b, 20-c, 21-a, 22-d, 23-b, 24-c, 25-a, 26-b,
27-b, 28-c, 29-b, 30-b, 31-a, 32-b, 33-b, 34-c,
35-a, 36-b, 37-c, 38-b, 39-b, 40-b, 41-a, 42-b,
43-d, 44-c, 45-a, 46-b, 47-a