GATE EE 2019 Set 1 — Question 56
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.NAT+2 / -0MediumGenerator & Motor CharacteristicsDC MachinesElectrical Machines
Electrical Machines → DC Machines → Generator & Motor Characteristics
Last updated
Question
A 220 V DC shunt motor takes 3 A at no-load. It draws 25 A when running at full-load at 1500 rpm. The armature and shunt resistances are 0.5 and 220 , respectively. The no-load speed in rpm (round off to two decimal places) is _____.
Correct answer
1564 to 1596
Solution
Given:
DC Shunt Motor
No-load current
Full-load current
Full-load speed
Armature resistance
Shunt resistance
Therefore,
The no-load speed is approximately . This value falls within the given range of to .
DC Shunt Motor
No-load current
Full-load current
Full-load speed
Armature resistance
Shunt resistance
1.Calculate shunt current:
2.Calculate no-load armature current:
3.Calculate no-load back EMF:
4.Calculate full-load armature current:
5.Calculate full-load back EMF:
6.Relate back EMF and speed:
For a DC shunt motor, back EMF is proportional to speed and flux (). Since it's a shunt motor, flux is approximately constant.Therefore,
7.Calculate no-load speed:
The no-load speed is approximately . This value falls within the given range of to .
Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE EE question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on DC Machines
2026 Set 1 Q17A 15 kVA, 1100 V/220 V, single-phase two-winding transformer is configured as a 1.32 kV/1.1 kV…2026 Set 1 Q20A certain application requires power at a frequency of , while the available grid…2026 Set 1 Q21Which one of the following options is correct regarding the typical double-squirrel-cage structure…2026 Set 1 Q22The figure shows the single-line diagram of a synchronous generator delivering …2026 Set 1 Q31A 220V/12V single-phase transformer is designed for use in India and rated 100 VA at 50 Hz. Later,…