Fundamentals of Electrical Engineering Unit 4 – Electrical Machines: important questions for AKTU
Unit 4 (Electrical Machines) questions that AKTU repeats most often. This unit carries about 26 marks per paper. Start with the repeated questions, then the most asked topics.
Most repeated Unit 4 questions
- What are the factors affecting speed of a DC motor? Compare lap and wave type armature winding. (10 marks, 2022, DC Machines) – also asked in 2022, 2023, 2024, 2025, 2026
- Derive an expression for torque in DC motor. A 230V DC series motor draws 50A current. Armature resistance 0.2Ω and series field winding resistance 0.1Ω. Calculate (i) brush voltage and (ii) back EMF. (10 marks, 2022, DC Machines) – also asked in 2022, 2023, 2024, 2025, 2026
- Why is an induction motor called a generalized transformer? Compare the induction motor with the transformer. (10 marks, 2022, Three Phase Induction Motor) – also asked in 2022, 2023, 2024, 2025, 2026
Most important Unit 4 topic
- DC Machines (Unit 4: Electrical Machines) – asked 21 times in 2022, 2023, 2024, 2025, 2026
Most asked Unit 4 topics
- DC Machines – asked 21 times
- Three Phase Induction Motor – asked 16 times
- Single Phase Induction Motor – asked 1 times
More Unit 4 previous year questions
- What is the basic principle of a DC motor? What is Back EMF Eb? (2 marks, 2026, DC Machines)
- A three phase induction motor has 6 poles and runs at 960 r.p.m. on full load, it is supplied from an alternator having 4 poles and running at 1500 rpm. Calculate the Full load Slip of the induction motor. (2 marks, 2026, Three Phase Induction Motor)
- How is a rotating magnetic field produced in a three phase induction motor? (7 marks, 2026, Three Phase Induction Motor)
- What are the applications of a DC motor? Discuss the factors influencing the selection of a DC motor. A 8 pole lap-wound DC generator has useful flux per pole 0.05 Wb, if the no load voltage at 400 rpm is 300V. Find the number of conductors on the armature periphery. (7 marks, 2026, DC Machines)
- (i) Why Single Phase Induction Motor is not Self Starting? (ii) What is Synchronous Machine? Also discuss the basic principle of synchronous machine. (7 marks, 2026, Three Phase Synchronous Machines)
Unit 4 syllabus topics
- DC Machines
- Three Phase Induction Motor
- Single Phase Induction Motor
- Three Phase Synchronous Machines