1. Which test is used to determine the efficiency of a traction motor? Field’s test Hopkinson’s test Retardation test Swinburne’s test 2. A 460 V series motor runs at 500 rpm taking a current of 40 A. Calculate the percentage change in torque if the load is changed so that the motor takes of …
DC Series Motor MCQ || DC Series Motor Questions and Answers Read More »
1. Which test is used to determine the efficiency of a traction motor? Field’s test Hopkinson’s test Retardation test Swinburne’s test 2. A 460 V series motor runs at 500 rpm taking a current of 40 A. Calculate the percentage change in torque if the load is changed so that the motor takes 30 …
DC Motor Types MCQ || Type of DC Motors Questions and Answers Read More »
1. A dc shunt motor has the following characteristics, Ra = 0.5 Ω, Rf = 200 Ω, base speed = 1000 rpm, rated voltage = 250 V. On no-load, it draws a current = 5 A. At what speed will this run while delivering a torque of 150 N.m? 881 rpm 920 rpm 950 rpm …
DC Motor Torque MCQ || DC Motor Torque Questions and Answers Read More »
1. The direction of rotation of a DC motor can be determined by: Ampere’s law Fleming’s left-hand rule Fleming’s right-hand rule Lenz’s law 2. What will happen if DC shunt motor is connected across AC supply? Will run at normal speed Will not run Will Run at a lower speed Burn due to heat …
Basics of DC Machine MCQ || DC machine Questions and Answers Read More »
1. The direction of rotation of a DC motor can be determined by: Ampere’s law Fleming’s left-hand rule Fleming’s right-hand rule Lenz’s law 2. What will happen if DC shunt motor is connected across AC supply? Will run at normal speed Will not run Will Run at a lower speed Burn due to heat …
DC Motor Principle MCQ || Objective Question with Answer for DC Motor Principle Read More »
1. The back EMF of the DC motor is ________ to speed. Square Directly proportional Inversely proportional Not equal 2. At certain loading conditions, back e.m.f. in DC motor was found half of the supply voltage. Then power delivered by DC motor is half of the rated power maximum minimum double of the rated …
DC Motor Back EMF MCQ || Back EMF in DC Motor Questions and Answers Read More »
1. When a DC motor generates maximum power, the ratio of applied voltage to back emf is 1:1 2:3 2:1 √2:1 2. A DC series motor running at the speed of 800 rpm draws 18 A from the supply. If the load is changed such that the current drawn by the motor is 55 …
1. When a DC motor generates maximum power, the ratio of applied voltage to back emf is 1:1 2:3 2:1 √2:1 2. A DC series motor running at the speed of 800 rpm draws 18 A from the supply. If the load is changed such that the current drawn by the motor is 55 …
1. Overheating of DC motors is mainly due to: Rough commutator Overloads Loose parts Absence of brushes 2. Which of the following is one of the categories of core loss in a DC machine? Friction loss Loss due to series field winding Windage loss Hysteresis loss 3. Iron losses in a D. C. …
DC Motor Losses MCQ || Losses in DC motor Questions and Answers Read More »
1. In electric braking of shunt motors, plugging is used to control Elevator Rolling Mills Printing Presses All of the above 2. Which of the following is the best braking method? Friction Electromechanical action Eddy-currents Electric braking 3. In which of the following cases dynamic breaking cannot be used? For large heavy loads …
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