Electric Traction — Part 1 MCQs with Explanations

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 .

Diesel locomotives typically have a horsepower range that allows them to efficiently pull heavy loads over long distances. The range of 1500 to 2500 horsepower is common for many diesel locomotives used in rail transport. This range provides the necessary power for both freight and passenger trains, ensuring reliable and effective performance.

10 m is the correct answer to “Overhead lines for power supply to tram cars are at a minimum height of”. This question is standard in competitive examination syllabi for Electric Traction.

Mainline service is the correct answer to “In case of ___________ free running and coasting periods are generally long.”. This question is standard in competitive examination syllabi for Electric Traction.

Varanasi is the correct answer to “In India diesel locomotives are manufactured at”. This question is standard in competitive examination syllabi for Electric Traction.

Chittaranjan is the correct answer to “Electric locomotives in India are manufactured at”. This question is standard in competitive examination syllabi for Electric Traction.

Jaipur is the correct answer to “Which of the following state capitals is not on broad gauge track”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “Specific energy consumption becomes”. This question is standard in competitive examination syllabi for Electric Traction.

Urban and suburban service is the correct answer to “Quadrilateral speed-time curve pertains to which of the following services”. This question is standard in competitive examination syllabi for Electric Traction.

Cleaned with sand is the correct answer to “The value of coefficient of adhesion will be high when rails are”. This question is standard in competitive examination syllabi for Electric Traction.

Main line is the correct answer to “Specific energy consumption is least in _______ service.”. This question is standard in competitive examination syllabi for Electric Traction.

Small turbo-generator is the correct answer to “In a steam locomotive electric power is provided through”. This question is standard in competitive examination syllabi for Electric Traction.

Facilitate in taking turns is the correct answer to “The wheels of a train, engine as well as bogies, are slightly tapered to”. This question is standard in competitive examination syllabi for Electric Traction.

50 Hz is the correct answer to “For 25 kV single phase system power supply frequency is”. This question is standard in competitive examination syllabi for Electric Traction.

More than that of D.C. locomotive is the correct answer to “For given maximum axle load tractive efforts of AC. locomotive will be”. This question is standard in competitive examination syllabi for Electric Traction.

More than 100 kmph is the correct answer to “The speed of a superfast train is”. This question is standard in competitive examination syllabi for Electric Traction.

0.25 is the correct answer to “The normal value of adhesion friction is”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “In main line service as compared to urban and suburban service”. This question is standard in competitive examination syllabi for Electric Traction.

Through individual generator of bogie and batteries is the correct answer to “Power for lighting in passenger coach, in a long distance electric train, is provided”. This question is standard in competitive examination syllabi for Electric Traction.

600 to 750 V is the correct answer to “The voltage used for suburban trains in D.C. system is usually”. This question is standard in competitive examination syllabi for Electric Traction.

Any of the above is the correct answer to “Vacuum is created by which of the following”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “Energy consumption in propelling the train is required for which of the following”. This question is standard in competitive examination syllabi for Electric Traction.

Both (B) and (C) is the correct answer to “Coefficient of adhesion reduces due to the presence of which of the following”. This question is standard in competitive examination syllabi for Electric Traction.

25 kV single phase A.C. is the correct answer to “Long distance railways use which of the following”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “The specific energy consumption of a train depends on which of the following”. This question is standard in competitive examination syllabi for Electric Traction.

Jolting and skidding is the correct answer to “The pulsating torque exerted by steam locomotives causes which of the following”. This question is standard in competitive examination syllabi for Electric Traction.

Low in case of D.C. traction than in the case of AC. traction is the correct answer to “Coefficient of adhesion is”. This question is standard in competitive examination syllabi for Electric Traction.

Regenerative braking on electric locomotives is the correct answer to “Which of the following braking systems on the locomotives is costly”. This question is standard in competitive examination syllabi for Electric Traction.

Factories for material transportation is the correct answer to “Battery operated trucks are used in”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “Main traction systems used in India are, those using”. This question is standard in competitive examination syllabi for Electric Traction.

Current surges after temporary switching off supply is the correct answer to “Series motor is not suited for traction duty due to which of the following account”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “Specific energy consumption is affected by which of the following factors”. This question is standard in competitive examination syllabi for Electric Traction.

Superfast trains is the correct answer to “Automatic signalling is used for which of the following trains”. This question is standard in competitive examination syllabi for Electric Traction.

22 V is the correct answer to “Which of the following is the voltage for single phase A.C. system”. This question is standard in competitive examination syllabi for Electric Traction.

40 Hz is the correct answer to “_________ frequency is not common in low frequency traction system”. This question is standard in competitive examination syllabi for Electric Traction.

Single phase supply is converted into three phase system is the correct answer to “Which of the following happens in Kando system”. This question is standard in competitive examination syllabi for Electric Traction.

0.16 km phps is the correct answer to “The coasting retardation is around”. This question is standard in competitive examination syllabi for Electric Traction.

All of the above is the correct answer to “Due to which of the following coefficient of adhesion improves”. This question is standard in competitive examination syllabi for Electric Traction.

Do all of the above is the correct answer to “Tractive effort is required to”. This question is standard in competitive examination syllabi for Electric Traction.