PAST PAPER Assistant Electric Inspector PPSC [SOLVED]
1. What is the unit of electrical resistance?
A) Ohm
B) Watt
C) Volt
D) Ampere
Answer: A) Ohm
2. Which law states that the current through a conductor between two points is directly proportional to the voltage across the two points?
A) Faraday’s Law
B) Ohm’s Law
C) Kirchhoff’s Law
D) Ampere’s Law
Answer: B) Ohm’s Law
3. In a series circuit, the total resistance is:
A) Equal to the sum of individual resistances
B) The product of individual resistances
C) The reciprocal of the sum of the reciprocals of individual resistances
D) Zero
Answer: A) Equal to the sum of individual resistances
4. What is the main function of a transformer?
A) To increase current
B) To increase voltage
C) To decrease resistance
D) To generate power
Answer: B) To increase voltage
5. What is the power factor of an ideal resistive circuit?
A) 0
B) 1
C) 0.5
D) ∞
Answer: B) 1
6. Which of the following is a semiconductor?
A) Copper
B) Silicon
C) Gold
D) Aluminum
Answer: B) Silicon
7. The magnetic field around a current-carrying conductor can be determined by:
A) Right-hand rule
B) Left-hand rule
C) Ampere’s circuital law
D) Biot-Savart law
Answer: A) Right-hand rule
8. The basic unit of capacitance is:
A) Henry
B) Farad
C) Ohm
D) Volt
Answer: B) Farad
9. What is the function of a diode?
A) To store energy
B) To convert AC to DC
C) To amplify signals
D) To measure current
Answer: B) To convert AC to DC
10. Which component is used to store electrical energy in an electric field?
A) Resistor
B) Capacitor
C) Inductor
D) Transformer
Answer: B) Capacitor
11. The frequency of the AC supply in Pakistan is:
A) 50 Hz
B) 60 Hz
C) 100 Hz
D) 120 Hz
Answer: A) 50 Hz
12. What does the term “kVA” stand for?
A) Kilo Volt Amperes
B) Kilo Volt Amperes Reactive
C) Kilowatt Volts Amperes
D) Kilowatt Amperes
Answer: A) Kilo Volt Amperes
13. Which device is used to measure electrical current?
A) Voltmeter
B) Ammeter
C) Ohmmeter
D) Wattmeter
Answer: B) Ammeter
14. The total power in a parallel circuit is equal to:
A) The sum of individual voltages
B) The sum of individual currents
C) The sum of individual powers
D) The product of individual resistances
Answer: C) The sum of individual powers
15. What type of circuit is used to protect electrical circuits from overload?
A) Capacitor
B) Inductor
C) Fuse
D) Transformer
Answer: C) Fuse
16. The phenomenon of electromagnetic induction was discovered by:
A) Thomas Edison
B) Nikola Tesla
C) Michael Faraday
D) James Clerk Maxwell
Answer: C) Michael Faraday
17. The primary function of an inductor is to:
A) Store electrical energy
B) Store magnetic energy
C) Convert electrical energy to mechanical energy
D) Convert mechanical energy to electrical energy
Answer: B) Store magnetic energy
18. The efficiency of an electric motor is defined as:
A) Output power divided by input power
B) Input power divided by output power
C) Input power minus output power
D) Output power plus input power
Answer: A) Output power divided by input power
19. Which type of machine converts electrical energy into mechanical energy?
A) Generator
B) Transformer
C) Motor
D) Rectifier
Answer: C) Motor
20. The unit of electrical energy is:
A) Joule
B) Watt
C) Volt
D) Ampere
Answer: A) Joule
21. Which type of signal is typically used in digital circuits?
A) Analog
B) Discrete
C) Continuous
D) Sinusoidal
Answer: B) Discrete
22. What does “RMS” stand for in electrical terms?
A) Random Measurement Signal
B) Root Mean Square
C) Resistor Measurement System
D) Reactive Measurement Signal
Answer: B) Root Mean Square
23. Which law states that the sum of the voltages around a closed loop is equal to zero?
A) Kirchhoff’s Voltage Law
B) Kirchhoff’s Current Law
C) Ohm’s Law
D) Faraday’s Law
Answer: A) Kirchhoff’s Voltage Law
24. The term “ground” in electrical systems refers to:
A) A source of voltage
B) A reference point for voltage
C) An overload protection
D) A storage battery
Answer: B) A reference point for voltage
25. What is the primary purpose of electrical insulation?
A) To increase conductivity
B) To protect against shock
C) To enhance power factor
D) To decrease capacitance
Answer: B) To protect against shock
26. In a three-phase system, how many conductors are typically used?
A) 1
B) 2
C) 3
D) 4
Answer: C) 3
27. What is the purpose of a circuit breaker?
A) To connect circuits
B) To measure voltage
C) To interrupt the flow of current
D) To increase current
Answer: C) To interrupt the flow of current
28. The unit of electrical power is:
A) Joule
B) Watt
C) Volt
D) Ampere
Answer: B) Watt
29. What is the primary function of a rectifier?
A) To store energy
B) To convert AC to DC
C) To amplify signals
D) To measure voltage
Answer: B) To convert AC to DC
30. The first law of thermodynamics is also known as:
A) Law of Conservation of Energy
B) Law of Energy Transformation
C) Law of Motion
D) Law of Heat Transfer
Answer: A) Law of Conservation of Energy
31. In a DC circuit, the power can be calculated using which formula?
A) P = VI
B) P = I²R
C) P = V²/R
D) All of the above
Answer: D) All of the above
32. What is the primary use of a capacitor in an AC circuit?
A) To increase power
B) To store and release energy
C) To convert AC to DC
D) To measure current
Answer: B) To store and release energy
33. The voltage drop across a resistor is given by:
A) V = IR
B) V = P/I
C) V = R/I
D) V = I²R
Answer: A) V = IR
34. What is the purpose of a busbar in electrical systems?
A) To store energy
B) To distribute power
C) To measure voltage
D) To connect resistors
Answer: B) To distribute power
35. Which type of relay is used to protect electrical circuits from overload?
A) Time delay relay
B) Thermal relay
C) Magnetic relay
D) Electromechanical relay
Answer: B) Thermal relay
36. What is the function of a fuse in an electrical circuit?
A) To reduce voltage
B) To store energy
C) To protect against overload
D) To increase current
Answer: C) To protect against overload
37. Which of the following is a common type of electrical generator?
A) Synchronous generator
B) Induction generator
C) Permanent magnet generator
D) All of the above
Answer: D) All of the above
38. What does the term “impedance” refer to in AC circuits?
A) Resistance only
B) Resistance and reactance
C) Voltage
D) Power
Answer: B) Resistance and reactance
39. The purpose of a voltage regulator is to:
A) Increase voltage
B) Decrease voltage
C) Maintain a constant voltage
D) Measure voltage
Answer: C) Maintain a constant voltage
40. What is the primary function of an oscilloscope?
A) To measure current
B) To measure voltage
C) To visualize waveforms
D) To store energy
Answer: C) To visualize waveforms
41. In electrical engineering, what is a phase shift?
A) A change in frequency
B) A change in amplitude
C) A difference in time between two signals
D) A change in resistance
Answer: C) A difference in time between two signals
42. The process of converting light into electricity is called:
A) Photoelectric effect
B) Electromagnetic induction
C) Photovoltaic effect
D) Thermal energy conversion
Answer: C) Photovoltaic effect
43. The principle of superposition applies to:
A) AC circuits only
B) DC circuits only
C) Linear circuits
D) Non-linear circuits
Answer: C) Linear circuits
44. The main advantage of using a three-phase system over a single-phase system is:
A) Higher voltage
B) Higher power factor
C) More power transmission capability
D) Simplicity
Answer: C) More power transmission capability
45. What is the main function of a circuit diagram?
A) To show physical connections
B) To represent the behavior of the circuit
C) To simplify complex circuits
D) To provide a visual representation of a circuit
Answer: D) To provide a visual representation of a circuit
46. What does the term “synchronous” refer to in synchronous motors?
A) Operating speed matches the supply frequency
B) Operating speed is independent of supply frequency
C) Only operates on DC supply
D) High power factor
Answer: A) Operating speed matches the supply frequency
47. What is the primary purpose of grounding in electrical systems?
A) To increase voltage
B) To provide a return path for current
C) To prevent electric shock
D) To improve power factor
Answer: C) To prevent electric shock
48. Which type of signal can be described as having infinite values within a range?
A) Digital
B) Analog
C) Discrete
D) Continuous
Answer: B) Analog
49. What is a common use of a relay in electrical circuits?
A) To store energy
B) To switch circuits on and off
C) To measure current
D) To increase voltage
Answer: B) To switch circuits on and off
50. What type of current does a battery provide?
A) Alternating current
B) Direct current
C) Pulsating current
D) Reactive current
Answer: B) Direct current
51. The term “load” in electrical engineering refers to:
A) The resistance in a circuit
B) The power supplied by a source
C) The electrical device consuming power
D) The voltage level in a circuit
Answer: C) The electrical device consuming power
52. In an electrical circuit, what does the term “short circuit” refer to?
A) A circuit with high resistance
B) A circuit with low voltage
C) A circuit with very low resistance
D) A circuit with very high voltage
Answer: C) A circuit with very low resistance
53. What is the principle behind operation of a transformer?
A) Electrolysis
B) Electromagnetic induction
C) Thermoelectric effect
D) Photoelectric effect
Answer: B) Electromagnetic induction
54. The main purpose of a power supply unit (PSU) is to:
A) Convert AC to DC
B) Store energy
C) Regulate voltage
D) All of the above
Answer: D) All of the above
55. The resonance in an RLC circuit occurs when:
A) Inductive reactance equals capacitive reactance
B) Resistance is zero
C) Current is maximum
D) Voltage is zero
Answer: A) Inductive reactance equals capacitive reactance
56. The unit of magnetic flux is:
A) Weber
B) Tesla
C) Henry
D) Ampere
Answer: A) Weber
57. In which type of motor is the rotor magnetized by induction?
A) Synchronous motor
B) Induction motor
C) Brushless motor
D) DC motor
Answer: B) Induction motor
58. What type of electrical machine is used to convert mechanical energy into electrical energy?
A) Generator
B) Motor
C) Transformer
D) Rectifier
Answer: A) Generator
59. The process of converting mechanical energy into electrical energy in a generator is known as:
A) Electromagnetic induction
B) Thermal energy conversion
C) Electromagnetic radiation
D) Kinetic energy conversion
Answer: A) Electromagnetic induction
60. A digital signal can have:
A) Infinite values
B) A finite number of values
C) Continuous values
D) None of the above
Answer: B) A finite number of values
61. Which of the following is NOT a passive component?
A) Resistor
B) Capacitor
C) Inductor
D) Transistor
Answer: D) Transistor
62. In a capacitor, the relationship between voltage and charge is:
A) Linear
B) Non-linear
C) Exponential
D) Constant
Answer: A) Linear
63. What does a potentiometer measure?
A) Voltage
B) Current
C) Resistance
D) Capacitance
Answer: A) Voltage
64. The primary characteristic of an ideal voltage source is:
A) Infinite internal resistance
B) Zero internal resistance
C) Constant current
D) Constant power
Answer: B) Zero internal resistance
65. In a capacitive circuit, if the frequency increases, the capacitive reactance:
A) Increases
B) Decreases
C) Remains constant
D) Becomes infinite
Answer: B) Decreases
66. What does the term “three-phase” refer to in electrical systems?
A) Three separate electrical circuits
B) Three voltages out of phase by 120 degrees
C) Three types of electrical components
D) Three times the frequency
Answer: B) Three voltages out of phase by 120 degrees
67. The function of a surge protector is to:
A) Increase voltage
B) Decrease voltage
C) Protect devices from voltage spikes
D) Convert AC to DC
Answer: C) Protect devices from voltage spikes
68. In electrical engineering, what is “thermal runaway”?
A) Excessive heating of a device leading to failure
B) A condition of low voltage
C) A condition of short circuit
D) A method of heat dissipation
Answer: A) Excessive heating of a device leading to failure
69. What is the purpose of a phase converter?
A) To convert AC to DC
B) To convert single-phase power to three-phase power
C) To measure phase angle
D) To increase voltage
Answer: B) To convert single-phase power to three-phase power
70. Which type of battery is commonly used in portable electronic devices?
A) Lead-acid battery
B) Lithium-ion battery
C) Nickel-cadmium battery
D) Alkaline battery
Answer: B) Lithium-ion battery
71. The phenomenon of skin effect in conductors refers to:
A) Loss of current capacity
B) Distribution of current density with depth
C) Increase in resistance with temperature
D) Decrease in inductance
Answer: B) Distribution of current density with depth
72. What is the primary use of a variable resistor?
A) To measure current
B) To control voltage
C) To control resistance
D) To provide constant voltage
Answer: C) To control resistance
73. In electrical circuits, “ground” is used primarily for:
A) Enhancing voltage
B) Ensuring safety
C) Providing energy
D) Increasing power factor
Answer: B) Ensuring safety
74. The purpose of a harmonic filter is to:
A) Remove DC components
B) Suppress harmonic distortion
C) Increase overall power
D) Reduce voltage
Answer: B) Suppress harmonic distortion
75. What is the maximum power transfer theorem?
A) Power is maximum when the load resistance equals the source resistance
B) Power is maximum when the load is zero
C) Power is maximum when the source voltage is minimized
D) Power is maximum when the frequency is at resonance
Answer: A) Power is maximum when the load resistance equals the source resistance
76. A single-phase induction motor is typically used in:
A) High-power applications
B) Low-power applications
C) Only DC applications
D) Only AC applications
Answer: B) Low-power applications
77. Which of the following describes the operation of a three-phase motor?
A) It operates at a higher voltage than single-phase motors
B) It provides a smoother torque output
C) It requires more maintenance than single-phase motors
D) It is less efficient than single-phase motors
Answer: B) It provides a smoother torque output
78. The equivalent circuit of a transformer consists of:
A) Primary and secondary resistances only
B) Magnetizing inductance and leakage reactance
C) Only resistance and capacitance
D) None of the above
Answer: B) Magnetizing inductance and leakage reactance
79. What is the effect of temperature on the resistance of a conductor?
A) Resistance increases with temperature
B) Resistance decreases with temperature
C) Resistance remains constant
D) Resistance fluctuates randomly
Answer: A) Resistance increases with temperature
80. The phenomenon of electromagnetic induction was discovered by:
A) Thomas Edison
B) Nikola Tesla
C) Michael Faraday
D) James Clerk Maxwell
Answer: C) Michael Faraday
81. Which country is known as the Land of the Rising Sun?
A) China
B) Japan
C) Thailand
D) India
Answer: B) Japan
82. Who was the founder of Pakistan?
A) Allama Iqbal
B) Liaquat Ali Khan
C) Muhammad Ali Jinnah
D) Zulfikar Ali Bhutto
Answer: C) Muhammad Ali Jinnah
83. What is the capital city of Pakistan?
A) Lahore
B) Karachi
C) Islamabad
D) Peshawar
Answer: C) Islamabad
84. Which river is known as the lifeline of Pakistan?
A) Indus River
B) Chenab River
C) Ravi River
D) Jhelum River
Answer: A) Indus River
85. Which of the following countries shares a border with Pakistan?
A) Afghanistan
B) Iran
C) India
D) All of the above
Answer: D) All of the above
86. What is the largest continent by area?
A) Africa
B) Asia
C) North America
D) Europe
Answer: B) Asia
87. The currency of Pakistan is called:
A) Rupee
B) Taka
C) Dollar
D) Dinar
Answer: A) Rupee
88. Who is the current Prime Minister of Pakistan?
A) Imran Khan
B) Shehbaz Sharif
C) Nawaz Sharif
D) Benazir Bhutto
Answer: B) Shehbaz Sharif (as of the latest available information)
89. What is the capital of the United States?
A) New York
B) Washington, D.C.
C) Los Angeles
D) Chicago
Answer: B) Washington, D.C.
90. In English grammar, which of the following is a synonym for “happy”?
A) Sad
B) Joyful
C) Angry
D) Tired
Answer: B) Joyful
91. What is 15% of 200?
A) 25
B) 30
C) 35
D) 40
Answer: B) 30
92. In Urdu, the word “کتاب” translates to:
A) Book
B) Pen
C) Paper
D) Table
Answer: A) Book
93. Which planet is known as the Red Planet?
A) Venus
B) Mars
C) Jupiter
D) Saturn
Answer: B) Mars
94. The process of converting data into a coded format is known as:
A) Decoding
B) Encryption
C) Compression
D) Transmission
Answer: B) Encryption
95. What is the boiling point of water in Celsius?
A) 50°C
B) 75°C
C) 100°C
D) 150°C
Answer: C) 100°C
96. In computer science, what does CPU stand for?
A) Central Processing Unit
B) Computer Personal Unit
C) Central Peripheral Unit
D) Control Processing Unit
Answer: A) Central Processing Unit
97. Which gas is essential for human respiration?
A) Carbon Dioxide
B) Oxygen
C) Nitrogen
D) Hydrogen
Answer: B) Oxygen
98. Who wrote the national anthem of Pakistan?
A) Allama Iqbal
B) Hafeez Jullundhri
C) Faiz Ahmed Faiz
D) Ahmed Faraz
Answer: B) Hafeez Jullundhri
99. Which of the following is a type of cloud?
A) Cumulus
B) Eucalyptus
C) Maple
D) Birch
Answer: A) Cumulus
100. What is the smallest prime number?
A) 0
B) 1
C) 2
D) 3
Answer: C) 2