1. Which of the following is NOT an advantage of electric traction?
A. Clean and pollution-free
B. Better acceleration and retardation
C. Low capital cost
D. High starting torque
Answer: C. Low capital cost
Explanation: Electric traction requires high initial infrastructure investment like overhead lines or third rail, making the capital cost high.
2. Regenerative braking is best suited for:
A. Diesel engines
B. Steam locomotives
C. Electric traction
D. Hydraulic drive
Answer: C. Electric traction
Explanation: Electric trains can return power to the grid during braking, making regenerative braking effective.
3. The ideal traction system should have:
A. High maintenance cost
B. Poor acceleration
C. Low starting torque
D. Rapid acceleration and deceleration
Answer: D. Rapid acceleration and deceleration
Explanation: For urban and suburban services, this is essential to minimize travel time.
4. Which of the following is used for mainline traction in India?
A. DC series motors
B. Three-phase induction motors
C. AC series motors
D. Shunt motors
Answer: C. AC series motors
Explanation: Single-phase AC series motors are widely used in Indian Railways for mainline services.
5. In regenerative braking, energy is:
A. Stored in a flywheel
B. Wasted as heat
C. Returned to the supply line
D. Stored in battery
Answer: C. Returned to the supply line
Explanation: In electric traction, regenerative braking returns kinetic energy to the power supply.
6. The average speed of a train is defined as:
A. Distance / Running time
B. Distance / Total time
C. Time / Distance
D. Total time / Distance
Answer: B. Distance / Total time
Explanation: Total time includes running time and stop time.
7. Tractive effort is:
A. The resistance due to train
B. The effort required to stop the train
C. The force required to overcome resistance and move the train
D. The energy required to operate the train
Answer: C. The force required to overcome resistance and move the train
Explanation: Tractive effort pulls the train against resistance like gradient, curve, and friction.
8. A speed-time curve helps in:
A. Reducing maintenance
B. Measuring voltage
C. Studying acceleration and braking patterns
D. Increasing power factor
Answer: C. Studying acceleration and braking patterns
Explanation: Speed-time curves give insights into train dynamics during operation.
9. The main drawback of DC traction is:
A. Complex substation
B. Poor performance at low speed
C. Need for frequent substations
D. Lack of control
Answer: C. Need for frequent substations
Explanation: Due to voltage drop and losses, DC systems need substations at short intervals.
10. The most economical schedule speed for urban service is:
A. 50–60 km/h
B. 25–30 km/h
C. 10–15 km/h
D. 80–90 km/h
Answer: B. 25–30 km/h
Explanation: Urban areas require frequent stops, making this speed range ideal.
11. The braking system used in electric locomotives includes:
A. Mechanical brake only
B. Regenerative and mechanical brake
C. Hydraulic only
D. Magnetic brake only
Answer: B. Regenerative and mechanical brake
Explanation: Both are used to maximize efficiency and safety.
12. Dead weight refers to:
A. Weight of passengers
B. Weight of locomotive only
C. Weight of train including payload
D. Weight that doesn’t contribute to tractive effort
Answer: D. Weight that doesn’t contribute to tractive effort
Explanation: Dead weight includes non-productive load of the train.
13. Specific energy consumption is measured in:
A. kWh/ton-km
B. N/km
C. kWh/km
D. Nm/sec
Answer: A. kWh/ton-km
Explanation: It measures energy required to move 1 ton of load over 1 km.
14. Which motor has best speed control?
A. Shunt motor
B. Series motor
C. Induction motor
D. Compound motor
Answer: A. Shunt motor
Explanation: Shunt motors offer easy and wide speed control.
15. Creeping in traction refers to:
A. Fast acceleration
B. Power failure
C. Wheel slipping without forward motion
D. Overload condition
Answer: C. Wheel slipping without forward motion
Explanation: Occurs when tractive effort exceeds adhesion limit.
16. Adhesion in traction is the ratio of:
A. Tractive effort to dead weight
B. Tractive effort to adhesive weight
C. Adhesive weight to speed
D. Adhesive weight to energy
Answer: B. Tractive effort to adhesive weight
Explanation: Determines how effectively the motor can transmit power without slipping.
17. The torque-speed characteristic of a DC series motor is:
A. Linear
B. Inverse
C. Hyperbolic
D. Exponential
Answer: C. Hyperbolic
Explanation: Torque decreases as speed increases, making it suitable for traction.
18. Pantograph is used in electric traction for:
A. Braking
B. Acceleration
C. Connecting to overhead wire
D. Speed control
Answer: C. Connecting to overhead wire
Explanation: Pantographs transfer electric power from overhead lines to the train.
19. Schedule speed is:
A. Always higher than average speed
B. Always lower than average speed
C. Equal to average speed
D. Average speed including stops
Answer: D. Average speed including stops
Explanation: It includes the effect of halts and is usually less than average running speed.
20. Which one is NOT a component of train resistance?
A. Gradient resistance
B. Rolling resistance
C. Air resistance
D. Braking resistance
Answer: D. Braking resistance
Explanation: Braking is not a resistance the train works against during motion.