Question Bank - Unit No.: 1
Program: B. TECH
Course Name: Electrical Machines 1
Course Code: 24ELE201
Academic year: 2025-2026 Sem/Year: 3rd/2nd year
Level A. Easy Questions (2 marks each)
S. No. Questions BL CO*
Q1 Define electro-mechanical energy conversion. 1 1
Q2 State the energy balance equation for an electromechanical system. 1 1
Q3 List two examples of singly excited magnetic field systems. 1 1
Q4 Write the expression for torque in a cylindrical air-gap machine. 1 1
Q5 Explain the concept of co-energy in a magnetic system. 2 1
Q6 Differentiate between energy and co-energy with a neat sketch. 2 1
Q7 Describe the role of magnetic field in producing force and torque. 2 1
Q8 Why is EMF generated in a machine when conductors move in a magnetic field? 2 1
Q9 Calculate the energy stored in an inductor of 10 mH carrying a current of 2 A. 3 1
Q10 A magnetic system stores 0.2 J of energy at 1 A. Find the inductance. 3 1
Q11 Derive the expression for force from the energy method in a magnetic field system. 3 1
Q12 Apply the concept of energy conversion to explain the working of a simple DC 3 1
motor.
Q13 Compare the force expressions obtained from energy method and co-energy 4 1
method.
Q14 Analyze how the cylindrical air gap affects the torque production in a machine. 4 1
Q15 Identify the differences between energy conversion via magnetic field and via 4 1
electric field
Q16 Distinguish between singly excited and multiply excited systems with examples. 4 1
Q17 Evaluate the advantages of using the co-energy method for torque calculation. 5 1
Q18 Critically examine the importance of the energy balance equation in machine 5 1
analysis.
Q19 Justify the need for considering both energy and co-energy in electro-mechanical 5 1
systems.
Q20 Design a simple electromechanical system model to demonstrate EMF generation 6 1
and explain its principle of operation.
Level B. Intermediate Questions (5 marks each)
Q21 Define electro-mechanical energy conversion and list its main applications. 1 1
, Q22 State the principle of energy balance equation in magnetic systems. 1 1
Q23 Write the expression for co-energy and explain its significance in energy 1 1
conversion.
Q24 List the conditions necessary for EMF generation in electrical machines. 1 1
Q25 Explain the concept of energy storage in a magnetic field system with a neat 2 1
sketch.
Q26 Differentiate between energy and co-energy in a singly excited magnetic system 2 1
Q27 Describe the role of cylindrical air-gap in torque production of rotating machines. 2 1
Q28 Summarize the process of force development in an electromagnetic field system. 2 1
Q29 A coil of 200 turns carries 2A current. If the flux linkage is 0.05 Wb-turn, calculate 3 1
the stored energy.
Q30 Determine the torque developed in a singly excited magnetic system given the 3 1
energy–co-energy relationship.
Q31 Apply the energy balance equation to show how mechanical output power is related 3 1
to electrical input and losses.
Q32 Calculate the induced EMF in a conductor moving in a magnetic field with given 3 1
values of velocity, flux density, and conductor length.
Q33 Break down the energy conversion process in a singly excited system into its key 4 1
stages.
Q34 Examine the differences between electromechanical torque and reluctance torque 4 1
with examples.
Q35 Justify the importance of energy and co-energy analysis in designing electrical 5 1
machines.
Q36 Critically evaluate the limitations of using a singly excited system model for 5 1
practical machines.
Q37 Design a conceptual model of a simple electromechanical energy converter using 6 1
the principles of magnetic energy storage and torque production.
Level C. Difficult Questions (10 marks each)
Q31 Define electro-mechanical energy conversion. Give two practical examples. 1 1
Q32 List and explain the key assumptions made in the analysis of magnetic field 1 1
systems.
Q33 Explain the concept of energy in a magnetic system with the help of relevant 2 1
equations.
Q34 Differentiate between energy and co-energy in electromagnetic systems. 2 1
Q35 Describe how EMF is generated in electrical machines according to 2 1
Faraday’s law.
Q36 A coil of 100 turns is wound on a magnetic core of reluctance 2000 A/Wb2000 \, 3 1
Program: B. TECH
Course Name: Electrical Machines 1
Course Code: 24ELE201
Academic year: 2025-2026 Sem/Year: 3rd/2nd year
Level A. Easy Questions (2 marks each)
S. No. Questions BL CO*
Q1 Define electro-mechanical energy conversion. 1 1
Q2 State the energy balance equation for an electromechanical system. 1 1
Q3 List two examples of singly excited magnetic field systems. 1 1
Q4 Write the expression for torque in a cylindrical air-gap machine. 1 1
Q5 Explain the concept of co-energy in a magnetic system. 2 1
Q6 Differentiate between energy and co-energy with a neat sketch. 2 1
Q7 Describe the role of magnetic field in producing force and torque. 2 1
Q8 Why is EMF generated in a machine when conductors move in a magnetic field? 2 1
Q9 Calculate the energy stored in an inductor of 10 mH carrying a current of 2 A. 3 1
Q10 A magnetic system stores 0.2 J of energy at 1 A. Find the inductance. 3 1
Q11 Derive the expression for force from the energy method in a magnetic field system. 3 1
Q12 Apply the concept of energy conversion to explain the working of a simple DC 3 1
motor.
Q13 Compare the force expressions obtained from energy method and co-energy 4 1
method.
Q14 Analyze how the cylindrical air gap affects the torque production in a machine. 4 1
Q15 Identify the differences between energy conversion via magnetic field and via 4 1
electric field
Q16 Distinguish between singly excited and multiply excited systems with examples. 4 1
Q17 Evaluate the advantages of using the co-energy method for torque calculation. 5 1
Q18 Critically examine the importance of the energy balance equation in machine 5 1
analysis.
Q19 Justify the need for considering both energy and co-energy in electro-mechanical 5 1
systems.
Q20 Design a simple electromechanical system model to demonstrate EMF generation 6 1
and explain its principle of operation.
Level B. Intermediate Questions (5 marks each)
Q21 Define electro-mechanical energy conversion and list its main applications. 1 1
, Q22 State the principle of energy balance equation in magnetic systems. 1 1
Q23 Write the expression for co-energy and explain its significance in energy 1 1
conversion.
Q24 List the conditions necessary for EMF generation in electrical machines. 1 1
Q25 Explain the concept of energy storage in a magnetic field system with a neat 2 1
sketch.
Q26 Differentiate between energy and co-energy in a singly excited magnetic system 2 1
Q27 Describe the role of cylindrical air-gap in torque production of rotating machines. 2 1
Q28 Summarize the process of force development in an electromagnetic field system. 2 1
Q29 A coil of 200 turns carries 2A current. If the flux linkage is 0.05 Wb-turn, calculate 3 1
the stored energy.
Q30 Determine the torque developed in a singly excited magnetic system given the 3 1
energy–co-energy relationship.
Q31 Apply the energy balance equation to show how mechanical output power is related 3 1
to electrical input and losses.
Q32 Calculate the induced EMF in a conductor moving in a magnetic field with given 3 1
values of velocity, flux density, and conductor length.
Q33 Break down the energy conversion process in a singly excited system into its key 4 1
stages.
Q34 Examine the differences between electromechanical torque and reluctance torque 4 1
with examples.
Q35 Justify the importance of energy and co-energy analysis in designing electrical 5 1
machines.
Q36 Critically evaluate the limitations of using a singly excited system model for 5 1
practical machines.
Q37 Design a conceptual model of a simple electromechanical energy converter using 6 1
the principles of magnetic energy storage and torque production.
Level C. Difficult Questions (10 marks each)
Q31 Define electro-mechanical energy conversion. Give two practical examples. 1 1
Q32 List and explain the key assumptions made in the analysis of magnetic field 1 1
systems.
Q33 Explain the concept of energy in a magnetic system with the help of relevant 2 1
equations.
Q34 Differentiate between energy and co-energy in electromagnetic systems. 2 1
Q35 Describe how EMF is generated in electrical machines according to 2 1
Faraday’s law.
Q36 A coil of 100 turns is wound on a magnetic core of reluctance 2000 A/Wb2000 \, 3 1
