Practice Working Principle (back Emf, Torque Production) (1.3.4.2) - DC and AC Electrical Machines
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Working Principle (Back EMF, Torque Production)

Practice - Working Principle (Back EMF, Torque Production)

Learning

Practice Questions

Test your understanding with targeted questions

Question 1 Easy

What does back EMF oppose in a DC motor?

💡 Hint: Think about the role of induced voltages.

Question 2 Easy

Define torque in the context of motors.

💡 Hint: Consider what causes the motor to rotate.

4 more questions available

Interactive Quizzes

Quick quizzes to reinforce your learning

Question 1

What is back EMF in a DC motor?

The voltage that assists armature current
The voltage that opposes the applied voltage
The voltage produced by the stator

💡 Hint: Think about what happens when an armature moves in a magnetic field.

Question 2

True or False: Torque is directly proportional to back EMF.

True
False

💡 Hint: Remember how torque develops in relation to current.

1 more question available

Challenge Problems

Push your limits with advanced challenges

Challenge 1 Hard

A DC motor with an armature current of 10 A and magnetic flux of 0.1 Wb produces a torque of 2 Nm. Calculate the constant (k_a) and explain its significance.

💡 Hint: Relate your answer back to the production of torque in practical applications.

Challenge 2 Hard

Given a motor starts with zero speed and back EMF is initially 0, explore how the armature current changes as speed increases to a rated value. Discuss operational efficiency.

💡 Hint: Reflect on the implications for power factor and energy consumption.

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Reference links

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