PSPU REVISED
1. What is the primary purpose of protective schemes in electrical systems?
A) To increase the operational efficiency of the system
✅ B) To prevent faults and ensure the system’s safety
C) To reduce system losses
D) To maintain voltage stability
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2. Which of the following is NOT a cause of overvoltage in electrical systems?
A) Lightning direct stroke
B) Indirect lightning stroke
✅ C) Fault in the transformer
D) Voltage surge due to switching operations
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3. In protection schemes, Current Transformers (CT) and Potential Transformers (PT) are used primarily for:
A) Measuring voltage levels
✅ B) Measuring current and voltage for protective relays
C) Maintaining system frequency
D) Reducing the overall system resistance
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4. What is the function of a Lightning Arrester in an electrical system?
A) To increase voltage levels during high current conditions
✅ B) To absorb and dissipate the energy from a lightning strike
C) To prevent overcurrent conditions
D) To control the frequency of electrical signals
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5. The main function of protective relays in power systems is to:
✅ a) Detect faults and initiate circuit breaker operation
b) Measure load current
c) Control voltage
d) Improve power factor
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6. The operating time of a relay depends on:
a) Type of relay
✅ b) Fault current magnitude
c) Relay location
d) System voltage
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7. Inverse time relays are used for:
✅ a) Overcurrent protection
b) Distance protection
c) Differential protection
d) Overvoltage protection
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8. HVDC breakers are specifically used to:
✅ A) Break direct current (DC) faults
B) Break high-voltage AC faults
C) Interrupt low-voltage faults
D) Control surge currents in the system
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9. When selecting an electric motor for a particular application, which of the following is a key factor in determining the motor choice?
A) The efficiency of the motor at full load
B) The power factor of the motor at idle
✅ C) The starting torque and speed characteristics required for the application
D) The color of the motor casing
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10. Magnetic Levitation (MAGLEV) trains primarily rely on:
A) Conventional track electrification systems
✅ B) The force of electromagnetic propulsion and repulsion for lifting and moving the train
C) Diesel engines for power
D) Braking through traditional friction mechanisms
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11. Which of the following is NOT a typical system of track electrification used in railway systems?
A) Third rail system
B) Overhead catenary system
C) Inductive power transfer system
✅ D) Ground-based magnetic resonance system
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12. The Pantograph collector in an overhead electrification system is used for:
A) Providing mechanical support to the overhead wires
✅ B) Collecting electric power from the contact wire for the train's operation
C) Insulating the train from the overhead equipment
D) Stabilizing the train’s speed during operation
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13. Which of the following lighting sources is most energy-efficient and has the longest lifespan?
A) Incandescent Lamps
B) Sodium Vapour Lamps
C) CFL (Compact Fluorescent Lamp)
✅ D) LED (Light Emitting Diode)
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14. In factory lighting, which of the following characteristics is most important to ensure safe and efficient operation?
A) High color temperature to ensure better visibility
✅ B) Uniform distribution of light with minimal glare
C) Use of incandescent bulbs for quick startup
D) High lumen output but low energy consumption
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15. Floodlighting is typically used for:
A) Providing general illumination for indoor spaces
✅ B) Illuminating large outdoor areas such as stadiums, buildings, or monuments
C) Lighting up small areas such as office desks
D) Enhancing visual comfort in low-light conditions in homes
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16. In modern lighting systems, the use of sensors and IoT for lighting control allows for:
A) Manual operation of each light individually
✅ B) Automatic adjustment of lighting based on occupancy, daylight, and activity
C) Increased energy consumption by maintaining lights on at all times
D) Eliminating the need for lamps and lighting equipment entirely
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17. Induction heating works on the principle of:
A) Direct current flow through a resistance coil to generate heat
✅ B) Magnetic fields inducing electric currents in the material, generating heat
C) High-frequency radiation absorbed by the material
D) The resistance of the material to an external electric field causing heating
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18. In electric arc furnaces, the heat is primarily generated by:
A) The resistance of the material to an alternating current
✅ B) Electric arcs formed between electrodes and the material
C) High-frequency currents applied directly to the metal
D) Heating coils placed around the furnace chamber
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19. Coreless induction furnaces are preferred in metal melting due to:
✅ A) Their ability to provide precise temperature control
B) Their large size and high output capacity
C) Their reliance on external heating elements for temperature regulation
D) Their simpler design and lack of a magnetic core, leading to less electrical loss
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20. Which of the following types of electric welding is most suitable for joining delicate or thin materials without excessive heat generation?
A) Resistance Welding
B) Arc Welding
✅ C) Ultrasonic Welding
D) Laser Beam Welding
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