Question

A dc separately excited motor has constant field current. The armature is fed from a single phase supply through a full converter. When α = 0, speed is 500 rpm. If α = 45°, the speed is likely to be

a.

about 350 rpm

b.

about 250 rpm

c.

about 175 rpm

d.

about 125 rpm

Answer: (d).about 125 rpm

Interact with the Community - Share Your Thoughts

Uncertain About the Answer? Seek Clarification Here.

Understand the Explanation? Include it Here.

Q. A dc separately excited motor has constant field current. The armature is fed from a single phase supply through a full converter. When α = 0, speed is 500 rpm. If α = 45°, the...

Similar Questions

Explore Relevant Multiple Choice Questions (MCQs)

Q. In a multiphase chopper, all choppers operate together.

Q. The terminals of a power MOSFET are called

Q. Assertion (A): The surge current which an SCR can withstand is much higher than rms on state current.

Reason (R): The duration of surge current is very small.

Q. Current derating may be necessary when thyristors are operating in

Q. If duty cycle is a and the load is α resistance R, the rms value of output voltage is

Q. For a BJT, α = 0.98, then β =

Q. Assertion (A): Power transistor has lower switching time than SCR

Reason (R): Power transistor has greater switching time than SCR

Q. A 3 kV circuit uses SCR of 800 V rating. If derating is 25%, the number of SCRs in series is

Q. The number of doped regions in a SCR is

Q. All inverters use forced commutation.

Q. In 180° mode of operation of a 3 phase bridge inverter, two thyristors conduct at one time.

Q. In a single phase full wave ac regulator the rms value of load current is 20 A load is purely resistive. Then

Q. A reactor is used in a dual converter operating in non-circulating current mode.

Q. In a 3 phase full wave regulator feeding resistance load connected in star, the possible range of firing angle α is

Q. Assertion (A): A dual converter may be circulating current type or non circulating current type.

Reason (R): In circulating current dual converter only one converter can be operated at one time.

Q. Current chopping leads to

Q. A 3 phase bridge inverter is fed by 400 V battery. The load is star connected and has a resistance of 10 Ω per phase. The peak value of load current is

Q. In an SCR, the anode current is controlled by

Q. The rated current of a thyristor is 40 A. The holding current will be about :

Q. A cycloconverter is

Recommended Subjects

Are you eager to expand your knowledge beyond Electronics and Communication Engineering? We've handpicked a range of related categories that you might find intriguing.

Click on the categories below to discover a wealth of MCQs and enrich your understanding of various subjects. Happy exploring!