Basic Electrical and Electronics (BEE) MCQ (Code :- 312302)

 BEE MCQ (312302)

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1. The ____ is defined as the region near a magnet within which the effect or influence of the magnet is felt.

a) Magnetic Field 

b) Magnetic Flux

c) Field Strength 

Ans. :- a)Magnetic Field 

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2. The magnetic lines of force are ____ and do not have any physical existence.

a) Imaginary 

b) Theoretical 

c) Virtual 

Ans. a)Imaginary 

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3. The magnetic flux density is measured in _____.

a) weber

b) weber/m²

c) weber/m³

Ans. b) weber/m²

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4. What is the fundamental difference between electric and magnetic circuits?

A) Electric circuits involve the flow of current, while magnetic circuits involve the flow of

magnetic flux.

B) Electric circuits involve the flow of magnetic flux, while magnetic circuits involve the flow

of current.

C) Electric circuits are always series, while magnetic circuits are always parallel.

D) Electric circuits are always parallel, while magnetic circuits are always series.

Ans.  A) Electric circuits involve the flow of current, while magnetic circuits involve the

flow of magnetic flux.

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5. In a series magnetic circuit, how are the magnetic reluctances connected?

A) In series

B) In parallel

C) In series-parallel combination

D) None of the above

Answer: A) In series

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6. According to Faraday's laws of electromagnetic induction, the induced electromotive force

(emf) in a circuit is directly proportional to:

A) The rate of change of current

B) The rate of change of magnetic flux

C) The resistance of the circuit

D) The voltage applied to the circuit

Answer: B) The rate of change of magnetic flux

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7. Dynamically induced emf occurs when:

A) There is a steady magnetic field

B) There is a change in the magnetic field with time

C) There is a change in the resistance of the circuit

D) There is no current flowing in the circuit

Answer: B) There is a change in the magnetic field with time

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8. Mutual inductance occurs between:

A) Two separate circuits with a shared magnetic field

B) Two conductors within the same circuit

C) A conductor and a permanent magnet

D) A resistor and an inductor

Answer: A) Two separate circuits with a shared magnetic field

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9. What is the period of an AC waveform?

A) The time it takes to complete one cycle

B) The amplitude of the waveform

C) The frequency of the waveform

D) The phase angle of the waveform

Answer: A) The time it takes to complete one cycle

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10. What does RMS value stand for in AC circuits?

A) Random Mean Square value

B) Root Mean Square value

C) Relative Mean Square value

D) Resistance Mean Square value

Answer: B) Root Mean Square value

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11. In a balanced three-phase system, how are the line currents related to the phase

currents?

A) Line currents are √3 times the phase currents

B) Line currents are 3 times the phase currents

C) Line currents are equal to the phase currents

D) Line currents are half the phase currents

Answer: A) Line currents are √3 times the phase currents

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12. What is the relationship between phase voltage and line voltage in a star-connected

balanced system?

A) Phase voltage is equal to line voltage

B) Phase voltage is √3 times the line voltage

C) Phase voltage is 3 times the line voltage

D) Phase voltage is half the line voltage

Answer: A) Phase voltage is equal to line voltage

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13. In a delta-connected balanced system, what is the relationship between phase current

and line current?

A) Phase current is equal to line current

B) Phase current is √3 times the line current

C) Phase current is 3 times the line current

D) Phase current is half the line current

Answer: A) Phase current is equal to line current

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14. Which type of connection is more commonly used in high-voltage transmission lines?

A) Star connection

B) Delta connection

C) Parallel connection

D) Series connection

Answer: B) Delta connection

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15. What is the term used to describe the combination of resistors, capacitors, and inductors in an electrical circuit?

A) Complex impedance

B) Simple impedance

C) Absolute impedance

D) Reactive impedance

Answer: A) Complex impedance

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16. Which of the following is NOT a passive component?

A) Resistor

B) Capacitor

C) Inductor

D) Transistor

Answer: D) Transistor

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17. A capacitor stores energy in the form of:

A) Magnetic field

B) Electric field

C) Mechanical motion

D) Thermal energy

Answer: B) Electric field

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18. The unit of inductance is:

A) Ohm

B) Farad

C) Henry

D) Joule

Answer: C) Henry

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19. What happens to the total inductance when inductors are connected in parallel?

A) It decreases

B) It increases

C) It remains the same

D) It becomes zero

Answer: A) It decreases

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20. What is the advantage of using a three-phase supply system over a single-phase supply

system?

A) Higher voltage

B) Lower current

C) Better power distribution

D) All of the above

Answer: D) All of the above

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21. Which type of connection is preferred for motors requiring both high starting torque and

high efficiency?

A) Star connection

B) Delta connection

C) Series connection

D) Parallel connection

Answer: B) Delta connection

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22. In a star-delta starter, the motor is initially connected in which configuration?

A) Star

B) Delta

C) Series

D) Parallel

Answer: A) Star

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23. Which of the following is a characteristic of a balanced three-phase system?

A) Equal phase voltages

B) Equal line currents

C) Equal phase angles

D) All of the above

Answer: D) All of the above

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24. What is the primary function of a transformer?

A) To convert AC to DC

B) To regulate voltage

C) To store energy

D) To change frequency

Answer: B) To regulate voltage

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25. What is the efficiency of an ideal transformer?

A) 100%

B) 0%

C) 50%

D) It depends on the load

Answer: A) 100%

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26. Which of the following is NOT a type of transformer core?

A) Iron core

B) Air core

C) Ferromagnetic core

D) Copper core

Answer: D) Copper core

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27. In a step-up transformer, the number of turns in the secondary coil is __________ the

number of turns in the primary coil.

A) Greater than

B) Less than

C) Equal to

D) Unrelated to

Answer: A) Greater than

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28. In a step-down transformer, the secondary voltage is __________ the primary voltage.

A) Greater than

B) Less than

C) Equal to

D) Unrelated to

Answer: B) Less than

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29. What is the purpose of the laminated core in a transformer?

A) To increase magnetic flux

B) To decrease eddy currents

C) To decrease insulation resistance

D) To increase hysteresis losses

Answer: B) To decrease eddy currents

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30. What is the frequency of the voltage supplied to most residential homes?

A) 50 Hz

B) 60 Hz

C) 100 Hz

D) 120 Hz

Answer: B) 60 Hz

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31. What is the working principle of a transformer?

A) Electromagnetic induction

B) Electrostatic induction

C) Piezoelectric effect

D) Photoelectric effect

Ans. :- A) Electromagnetic induction

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32. Which equation represents the relationship between the primary and secondary voltages

in a transformer?

A) V = IR

B) V = L di/dt

C) V1/V2 = N1/N2

D) V = I*R

Ans. :- C) V1/V2 = N1/N2

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33. In a transformer, the ratio of the number of turns in the primary coil to the number of turns

in the secondary coil is called:

A) Transformation ratio

B) Voltage ratio

C) Current ratio

D) Resistance ratio

Ans. = A) Transformation ratio

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34. Which loss occurs in a transformer due to the resistance of the windings?

A) Eddy current loss

B) Hysteresis loss

C) Copper loss

D) Core loss

Ans. = C) Copper loss

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35. What is the main function of the commutator in a DC motor?

A) To change AC to DC

B) To reverse the direction of rotation

C) To control the speed

D) To provide mechanical support

Ans. = B) To reverse the direction of rotation

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36. Which material is commonly used for making the armature of a DC motor?

A) Copper

B) Aluminum

C) Iron

D) Carbon

Ans. = A) Copper

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37. The principle of operation of a DC motor is based on:

A) Electromagnetic induction

B) Fleming's left-hand rule

C) Faraday's law

D) Coulomb's law

Ans. = B) Fleming's left-hand rule

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38. Which type of DC motor has its field winding connected in parallel with the armature

winding?

A) Shunt motor

B) Series motor

C) Compound motor

D) Separately excited motor

Ans. = A) Shunt motor

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39. The speed of a DC shunt motor is generally:

A) Constant

B) Proportional to the load

C) Inversely proportional to the load

D) Zero

Ans. = A) Constant

40. In a compound motor, if both the series and shunt fields aid each other, it is called:

A) Cumulative compound motor

B) Differential compound motor

C) Shunt compound motor

D) Series compound motor

Ans. = A) Cumulative compound motor

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41. The principle of operation of a universal motor is based on:

A) Electromagnetic induction

B) Fleming's right-hand rule

C) Faraday's law

D) Commutation

Ans. = D) Commutation

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42. How can the direction of rotation be reversed in a universal motor?

A) By changing the polarity of the field winding

B) By reversing the direction of current flow in the armature winding

C) By changing the supply voltage

D) By changing the frequency of the supply

Ans. =  B) By reversing the direction of current flow in the armature winding

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43. Which type of motor is suitable for applications requiring high starting torque and precise positioning, such as in robotics?

A) Shunt motor

B) Series motor

C) Compound motor

D) Stepper motor

Ans. =  D) Stepper motor

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44. What is the principle behind the operation of a stepper motor?

A) Electromagnetic induction

B) Magnetic hysteresis

C) Variable reluctance

D) Permanent magnetism

Ans. =  C) Variable reluctance

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45. Which type of stepper motor has the highest accuracy but the lowest speed?

A) Variable reluctance stepper motor

B) Permanent magnet stepper motor

C) Hybrid stepper motor

D) VR hybrid stepper motor

Ans. =  A) Variable reluctance stepper motor

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46. What is the primary function of the stator in an electrical machine?

A) To provide mechanical support

B) To rotate

C) To produce a magnetic field

D) To induce current

Ans. =  C) To produce a magnetic field

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47. Which of the following losses occurs in the core of a transformer due to alternating

magnetization and demagnetization?

A) Eddy current loss

B) Copper loss

C) Hysteresis loss

D) Mechanical loss

Ans. =  C) Hysteresis loss

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48. Which type of DC motor has its field winding connected in series with the armature

winding?

A) Shunt motor

B) Series motor

C) Compound motor

D) Separately excited motor

Ans. =  B) Series motor

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49. In a compound motor, if the series field opposes the shunt field, it is called:

A) Cumulative compound motor

B) Differential compound motor

C) Shunt compound motor

D) Series compound motor

Ans. =  B) Differential compound motor

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50. Which type of motor is often used in handheld power tools due to its compact size and

high power-to-weight ratio?

A) Shunt motor

B) Series motor

C) Compound motor

D) Universal motor

Ans. =  D) Universal motor

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51. The efficiency of a transformer is maximum when:

A) Copper losses are minimum

B) Iron losses are minimum

C) Total losses are minimum

D) Core losses are maximum

Ans. =  C) Total losses are minimum

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52. Which of the following is not a type of DC motor?

A) Permanent magnet motor

B) Synchronous motor

C) Shunt motor

D) Series motor

Ans. =  B) Synchronous motor

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53. What is the function of brushes in a DC motor?

A) To control the speed

B) To reverse the direction of rotation

C) To provide electrical contact with the commutator

D) To support the armature

Ans. =  C) To provide electrical contact with the commutator

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54. Which type of DC motor has a high starting torque but poor speed regulation?

A) Shunt motor

B) Series motor

C) Compound motor

D) Separately excited motor

Ans. =  B) Series motor

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55. The speed of a universal motor is usually controlled by varying the:

A) Voltage

B) Current

C) Resistance

D) Capacitance

Ans. =  A) Voltage

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56. Which type of stepper motor has the highest resolution and accuracy?

A) Variable reluctance stepper motor

B) Permanent magnet stepper motor

C) Hybrid stepper motor

D) VR hybrid stepper motor

Ans. =  C) Hybrid stepper motor

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57. The function of a commutator in a DC motor is to:

A) Control the speed

B) Change AC to DC

C) Reverse the direction of rotation

D) Convert electrical energy into mechanical energy

Ans. =  C) Reverse the direction of rotation

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58. The main advantage of a compound motor over a shunt motor is:

A) Better speed regulation

B) Higher starting torque

C) Lower maintenance

D) Smaller size

Ans. =  B) Higher starting torque

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59. Which of the following is not a type of losses in a transformer?

A) Copper losses

B) Eddy current losses

C) Hysteresis losses

D) Voltage losses

Ans. =  D) Voltage losses

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60. The efficiency of a transformer can be calculated by the ratio of:

A) Output power to input power

B) Input voltage to output voltage

C) Output current to input current

D) Input power to output power

Ans. =  A) Output power to input power

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61. In a DC motor, the torque produced is directly proportional to:

A) Armature current

B) Back EMF

C) Field current

D) Armature resistance

Ans. =  A) Armature current

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62. The direction of rotation of a DC motor can be reversed by:

A) Increasing the supply voltage

B) Decreasing the supply voltage

C) Reversing the polarity of either the field or armature winding

D) Increasing the resistance in the circuit

Ans. =  C) Reversing the polarity of either the field or armature winding

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63. Which type of DC motor is commonly used in electric trains and cranes?

A) Shunt motor

B) Series motor

C) Compound motor

D) Separately excited motor

Ans. =  B) Series motor

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64. What is the function of the field winding in a DC motor?

A) To induce voltage

B) To provide mechanical support

C) To produce the magnetic field

D) To control the speed

Ans. =  C) To produce the magnetic field

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65. The speed of a DC motor can be controlled by:

A) Varying the supply voltage

B) Varying the armature resistance

C) Changing the number of poles

D) All of the above

Ans. =  D) All of the above

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66. Which type of DC motor has both series and shunt fields connected to the armature?

A) Cumulative compound motor

B) Differential compound motor

C) Shunt compound motor

D) Series compound motor

Ans. =  C) Shunt compound motor

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67. What is the main advantage of a universal motor over other types of motors?

A) Higher efficiency

B) Lower cost

C) Ability to operate on both AC and DC

D) Longer lifespan

Ans. =  C) Ability to operate on both AC and DC

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68. Which type of stepper motor does not have permanent magnets?

A) Permanent magnet stepper motor

B) Variable reluctance stepper motor

C) Hybrid stepper motor

D) VR hybrid stepper motor

Ans. =  B) Variable reluctance stepper motor

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69. The rotor in a stepper motor rotates in discrete steps because of:

A) Magnetic field reversal

B) Mechanical gears

C) Commutation

D) Pulse signals to windings

Ans. =  D) Pulse signals to windings

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70. Which type of stepper motor combines the features of variable reluctance and

permanent magnet motors?

A) Permanent magnet stepper motor

B) Variable reluctance stepper motor

C) Hybrid stepper motor

D) VR hybrid stepper motor

Ans. =  C) Hybrid stepper motor

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