Fundamentals of Electrical Engineering Unit 4 – Electrical Machines: AKTU previous year questions
41 AKTU questions from Unit 4 (Electrical Machines) asked in 2022–2026, tagged by marks, year and topic. In short: about 26 marks of every paper come from this unit; the most asked topic is DC Machines (21 times); 36 questions came back in a later year. The latest ones are listed below; on the page you can filter them by 2-mark or long questions, topic and repeats.
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)
- A 3-phase 440 V, 50 Hz induction motor has a 4% slip. What will be the Frequency of the rotor current? (2 marks, 2025, Three Phase Induction Motor)
- Define the commutator in DC machine. (2 marks, 2025, DC Machines)
- A three phase 50Hz, 2 pole induction motor has a full speed of 2860 rpm. What is the (i) synchronous speed (ii) slip of the induction motor and (iii) rotor emf frequency? (7 marks, 2025, Three Phase Induction Motor)
- Derive the torque equation for DC machines. (7 marks, 2025, DC Machines)
- Draw and explain the torque-slip characteristics of a 3-Φ induction motor indicating the starting torque, the maximum torque and operating region. (7 marks, 2025, Three Phase Induction Motor)
- Explain the working principle of DC generator and also Derive the EMF equation of DC generator. (7 marks, 2025, DC Machines)
- A six-pole, wave-connected armature of a DC machine has 300 Conductors and runs at 1000 rpm. The emf generated on the open circuit is 400V. Determine the useful flux per pole. (7 marks, 2025, DC Machines)
Most asked Unit 4 topics
- DC Machines – asked 21 times
- Three Phase Induction Motor – asked 16 times
- Single Phase Induction Motor – asked 1 times
Unit 4 question pattern
- 2-mark questions: 13 asked in 2022–2026
- 7-mark questions: 21 asked in 2022–2026
- 10-mark questions: 7 asked in 2022–2026
- About 26 marks from Unit 4 in every paper
- 36 questions were asked again in a later year
Unit 4 questions year by year
- 2026: 5 Unit 4 questions asked (25 marks across that year's papers)
- 2025: 8 Unit 4 questions asked (46 marks across that year's papers)
- 2024: 8 Unit 4 questions asked (46 marks across that year's papers)
- 2023: 8 Unit 4 questions asked (46 marks across that year's papers)
- 2022: 12 Unit 4 questions asked (80 marks across that year's papers)