Introduction to Electrical Engineering MCQs
1. What is the SI unit of electric charge?
A) Volt
B) Ampere
C) Coulomb
D) Ohm
Answer: C) Coulomb
2. Which of the following materials is a good conductor of electricity?
A) Glass
B) Rubber
C) Copper
D) PVC
Answer: C) Copper
3. In which type of circuit are the elements connected end-to-end with no branching?
A) Series
B) Parallel
C) Series-parallel
D) None of the above
Answer: A) Series
4. What is the unit of electrical resistance?
A) Farad
B) Ohm
C) Henry
D) Tesla
Answer: B) Ohm
5. Which law states that the voltage across a resistor is directly proportional to the current passing through it, assuming constant temperature?
A) Ohm’s law
B) Kirchhoff’s voltage law
C) Kirchhoff’s current law
D) Watt’s law
Answer: A) Ohm’s law
6. Which type of material allows electric charges to flow freely?
A) Insulator
B) Semiconductor
C) Conductor
D) Dielectric
Answer: C) Conductor
7. What is the SI unit of electric potential difference?
A) Volt
B) Ampere
C) Coulomb
D) Ohm
Answer: A) Volt
8. Which instrument is used to measure electric current?
A) Voltmeter
B) Ammeter
C) Galvanometer
D) Multimeter
Answer: B) Ammeter
9. What does the acronym AC stand for in electrical terms?
A) Alternating Current
B) Alternating Charge
C) Alternating Capacitance
D) Alternating Circuit
Answer: A) Alternating Current
10. What is the standard voltage of a typical household electrical outlet in most countries?
A) 110 V
B) 220 V
C) 240 V
D) 120 V
Answer: B) 220 V
11. Which device is used to store electrical energy temporarily in an electrical circuit?
A) Capacitor
B) Inductor
C) Resistor
D) Transformer
Answer: A) Capacitor
12. What is the purpose of a diode in an electrical circuit?
A) To store energy
B) To control voltage
C) To rectify AC to DC
D) To amplify signals
Answer: C) To rectify AC to DC
13. Which law states that the algebraic sum of currents entering and leaving a junction is zero?
A) Ohm’s law
B) Kirchhoff’s voltage law
C) Kirchhoff’s current law
D) Watt’s law
Answer: C) Kirchhoff’s current law
14. What type of motor operates on the principle that the torque is produced due to the interaction between the magnetic field of the stator and rotor?
A) Induction motor
B) DC motor
C) Synchronous motor
D) Stepper motor
Answer: A) Induction motor
15. Which device is used to protect electrical appliances from power surges?
A) Fuse
B) Circuit breaker
C) Transformer
D) Relay
Answer: B) Circuit breaker
16. In an electrical circuit, what does a resistor do?
A) Increases current
B) Decreases voltage
C) Stores energy
D) Limits current flow
Answer: D) Limits current flow
17. Which phenomenon occurs when a voltage is induced in a conductor by a changing magnetic field?
A) Inductance
B) Capacitance
C) Resistance
D) Electromagnetic induction
Answer: D) Electromagnetic induction
18. What is the unit of frequency?
A) Hertz
B) Watt
C) Joule
D) Tesla
Answer: A) Hertz
19. Which law states that the total electric flux through a closed surface is equal to the charge enclosed divided by the permittivity of the medium?
A) Gauss’s law
B) Coulomb’s law
C) Ampère’s law
D) Faraday’s law
Answer: A) Gauss’s law
20. Which type of electrical generator produces a DC output?
A) Alternator
B) Dynamo
C) Transformer
D) Rectifier
Answer: B) Dynamo
21. What is the function of an inductor in an electrical circuit?
A) To store energy
B) To control voltage
C) To provide resistance
D) To store magnetic energy
Answer: D) To store magnetic energy
22. What is the primary function of a transformer in an electrical circuit?
A) To convert AC to DC
B) To increase voltage
C) To decrease current
D) To amplify signals
Answer: B) To increase voltage
23. Which type of material has electrical properties between those of conductors and insulators?
A) Conductor
B) Insulator
C) Semiconductor
D) Dielectric
Answer: C) Semiconductor
24. Which component is used to store electrical charge?
A) Resistor
B) Capacitor
C) Inductor
D) Transformer
Answer: B) Capacitor
25. What is the SI unit of power?
A) Volt
B) Watt
C) Ampere
D) Ohm
Answer: B) Watt
26. Which device converts electrical energy into mechanical energy?
A) Capacitor
B) Resistor
C) Motor
D) Diode
Answer: C) Motor
27. What is the unit of electrical conductance?
A) Ohm
B) Siemens
C) Henry
D) Coulomb
Answer: B) Siemens
28. Which type of electrical circuit is characterized by multiple paths for current flow?
A) Series
B) Parallel
C) Series-parallel
D) None of the above
Answer: B) Parallel
29. Which law states that the sum of the voltages in a closed loop is equal to the sum of the voltage drops?
A) Ohm’s law
B) Kirchhoff’s voltage law
C) Kirchhoff’s current law
D) Watt’s law
Answer: B) Kirchhoff’s voltage law
30. Which type of material has very high resistance to the flow of electric current?
A) Conductor
B) Insulator
C) Semiconductor
D) Dielectric
Answer: B) Insulator
31. What is the purpose of a rectifier in an electrical circuit?
A) To store energy
B) To convert AC to DC
C) To amplify signals
D) To control voltage
Answer: B) To convert AC to DC
32. Which law states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them?
A) Ohm’s law
B) Coulomb’s law
C) Faraday’s law
D) Ampère’s law
Answer: B) Coulomb’s law
33. What is the SI unit of electrical capacitance?
A) Farad
B) Henry
C) Tesla
D) Gauss
Answer: A) Farad
34. Which type of electrical connection increases the total resistance compared to individual resistances?
A) Series
B) Parallel
C) Series-parallel
D) It depends on the resistances
Answer: A) Series
35. What is the purpose of a fuse in an electrical circuit?
A) To regulate voltage
B) To store energy
C) To protect against overcurrent
D) To convert AC to DC
Answer: C) To protect against overcurrent
36. Which device is used to change the voltage level in an electrical circuit?
A) Fuse
B) Transformer
C) Relay
D) Capacitor
Answer: B) Transformer
37. What is the unit of magnetic flux density?
A) Tesla
B) Weber
C) Gauss
D) Ampere-turn
Answer: A) Tesla
38. Which law relates the magnetic field around a closed loop to the electric current passing through the loop?
A) Ohm’s law
B) Coulomb’s law
C) Ampère’s law
D) Faraday’s law
Answer: C) Ampère’s law
39. What is the function of a relay in an electrical circuit?
A) To convert AC to DC
B) To amplify signals
C) To protect against overcurrent
D) To control high-power circuits with low-power signals
Answer: D) To control high-power circuits with low-power signals
40. Which component is used to convert mechanical motion into electrical energy?
A) Capacitor
B) Resistor
C) Generator
D) Diode
Answer: C) Generator
41. What is the SI unit of magnetic flux?
A) Weber
B) Tesla
C) Gauss
D) Ampere-turn
Answer: A) Weber
42. Which law states that the induced electromotive force (emf) in any closed circuit is equal to the rate of change of magnetic flux through the circuit?
A) Ohm’s law
B) Coulomb’s law
C) Ampère’s law
D) Faraday’s law
Answer: D) Faraday’s law