Recent questions tagged traction

Description : The motor used for electric traction is  (1) D.C. shunt motor (3) D.C. series motor  (2) D.C. compound motor (4) Synchronous motor

Last Answer : The motor used for electric traction is D.C. series motor

Description : In quadrilateral speed-time curve of electric traction system, the accelerations during successive time periods are ______ respectively.  (A) positive, negative and negative (B) positive, zero and negative (C) positive, positive and negative (D) positive, negative and zero

Last Answer : In quadrilateral speed-time curve of electric traction system, the accelerations during successive time periods are positive, negative and negative respectively. 

Description : In electric traction for a trapezoidal speed-time curve, the time period is (A) free running speed period = constant speed period (B) free running period = coasting period (C) free running period + coasting period = constant speed period (D) average speed period = scheduled speed period

Last Answer : In electric traction for a trapezoidal speed-time curve, the time period is free running period + coasting period = constant speed period

Description : Which of the following test is usually conducted to determine the efficiency of traction motors ? (A) Field’s test (B) Swinburne’s test (C) Hopkinson’s test (D) Retardation test.

Last Answer : Which of the following test is usually conducted to determine the efficiency of traction motors ? (A) Field’s test (B) Swinburne’s test (C) Hopkinson’s test (D) Retardation test.

Last Answer : An ideal traction system should have easy speed control, high starting tractive effort, equipment capable of with standing large temporary loads.

Last Answer : The D.C. motors preferred for traction applications beacuse the speed is inversely proportional to the torque and the torque is proportional to square of armature current.