GATE 2023 Electrical Machines Quiz 31

A long shunt compound wound motor is having shunt field resistance, series field resistance and armature resistance of 300 Ω, 0.8 Ω and 0.6 Ω respectively. If the motor is drawing 60A at 500V, What is the voltage drop across series field resistance?

Consider the following statements regarding the speed control of dc motor. Which of the followings are correct?

If the applied voltage to a DC motor is 240 V, then back emf for maximum power developed is-

By flux control method of speed control of a dc series motor, we can obtain speeds:

A 240V series takes 50A when giving its rated output at 1000rpm. Its resistance is 0.8Ω. Then, find the resistance that must be added in series of armature to obtain rated torque at starting _________Ω.

A 230 V DC series motor takes 40A when giving its rated output at 1000 rpm.

Its resistance is 0.25Ω. The value of resistance that must be added to obtain rated torque at 800 rpm is __________ Ω.