Electric Traction MCQ Questions & Answers | Electrical Engineering

In electric traction (and specifically steam locomotives), the speed is primarily controlled by adjusting the input power to the engine.

This is done by regulating the flow of steam entering the engine cylinders, which directly controls the force generated and hence the speed.

Flywheel is used for smoothing rotational motion, not for speed control.

Gear box is generally not used in locomotives in the same way as in automobiles for speed variation.

Applying brakes reduces speed but is not a method of controlling or maintaining desired operating speed.

Therefore, the correct method of controlling locomotive speed is regulating steam flow to the engine.

Electric traction refers to the use of electric power to propel vehicles such as trains, trams, and electric buses. It offers several advantages over other methods of traction:

1. Faster acceleration: Electric traction systems can provide high torque at low speeds, allowing for faster acceleration of vehicles compared to diesel or steam-powered traction.

2. No pollution problems: Electric traction systems produce less or zero emissions at the point of use, contributing to cleaner air quality and reduced environmental impact compared to diesel or steam engines.

3. Better braking action: Electric traction systems can employ regenerative braking, where energy from braking is captured and fed back into the power supply system, improving efficiency and reducing wear on braking components.

Option A: Faster acceleration is correct because electric traction systems generally offer faster acceleration due to the characteristics of electric motors.

Option B: No pollution problems is correct because electric traction systems are cleaner and produce fewer emissions compared to diesel or steam-powered traction.

Option C: Better braking action is correct because electric traction systems can utilize regenerative braking, which is more efficient and provides better control over braking compared to traditional friction brakes.

Therefore, the correct answer is All of the above.