PAST PAPER Assistant Electric Inspector PPSC [SOLVED]

By: Prof. Dr. Fazal Rehman | Last updated: October 31, 2024

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