You are here:
  1. / iCalculator
  2. / Magnetism
  3. / Induction And Energy Transfers
  4. / Emf

Menu

Physics Lesson 16.10.3 - Induced Emf

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

★★★★★ [ 1 Votes ]

Welcome to our Physics lesson on Induced Emf, this is the third lesson of our suite of physics lessons covering the topic of Induction and Energy Transfers, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.

Induced Emf

Obviously, since there is a current induced in the coil, there is an induced emf in it as well. We must apply the Faraday's Law for to find this induced emf. If we denote the length of the loop by l, and its width by w, we have:

ΦM = B ∙ A
= B ∙ l ∙ w

Let's denote the part of coil's length inside the magnetic field by a as shown in the figure. The value of a varies from 0 to l depending on the position of the coil relative to the magnetic field.

Physics Tutorials: This image provides visual information for the physics tutorial Induction and Energy Transfers

As we move the coil due right, the part of its length inside the field (a therefore) decreases. As a result, the magnetic flux through the coil decreases too, as stated earlier. From Faraday's Law, it is known that any change in flux is accompanied by the induction of an emf in the coil. The magnitude of this induced emf is

εi = ∆ΦM/Δt
= B ∙ w ∙ ∆l/∆t
= B ∙ w ∙ v

where v is the moving speed of the coil.

Example 1

A rectangular coil (as the one shown above in theory) is 20 cm long and 15 cm wide. The coil is pulled at a constant force and speed and as a result, it takes 5 seconds to the coil to move out from the 0.2 T magnetic field, the lines of which are perpendicular to the coil's plane.

Physics Tutorials: This image provides visual information for the physics tutorial Induction and Energy Transfers
  1. What is the emf induced in the coil?
  2. What is the power delivered by the magnetic force if the pulling force is 4N?

Solution 1

Clues:

l = 20 cm = 0.20 m
w = 15 cm = 0.15 m
B = 0.2 T
Δt = 5 s
F = 4 N

  1. The induced emf in the coil is
    εi = ∆ΦM/Δt
    = B ∙ w ∙ ∆l/∆t
    = (0.2 T) ∙ (0.15 m) ∙ (0.20 m-0 m)/5 s
    = 0.0012 V
  2. We must work out the moving velocity of coil first in order to calculate the power delivered by the magnetic force. Thus, since the coil is moving at constant speed, we have
    v = ∆l/∆t
    = 0.20 m/5 s
    = 0.04 m/s
    Yet, since the coil moves at constant speed, the pulling force is balanced by the magnetic force. Hence, we have
    PM = FM ∙ v
    = F ∙ v
    = (4 N) ∙ (0.04 m/s)
    = 0.16 W

You have reached the end of Physics lesson 16.10.3 Induced Emf. There are 6 lessons in this physics tutorial covering Induction and Energy Transfers, you can access all the lessons from this tutorial below.

More Induction and Energy Transfers Lessons and Learning Resources

Magnetism Learning Material
Tutorial IDPhysics Tutorial TitleTutorialVideo
Tutorial		Revision
Notes		Revision
Questions
16.10Induction and Energy Transfers
Lesson IDPhysics Lesson TitleLessonVideo
Lesson
16.10.1Induction and Energy Transfer
16.10.2Rate of Work (Power)
16.10.3Induced Emf
16.10.4Induced Current
16.10.5Power and Energy
16.10.6Eddy Currents

Whats next?

Enjoy the "Induced Emf" physics lesson? People who liked the "Induction and Energy Transfers lesson found the following resources useful:

  1. Emf Feedback. Helps other - Leave a rating for this emf (see below)
  2. Magnetism Physics tutorial: Induction and Energy Transfers. Read the Induction and Energy Transfers physics tutorial and build your physics knowledge of Magnetism
  3. Magnetism Revision Notes: Induction and Energy Transfers. Print the notes so you can revise the key points covered in the physics tutorial for Induction and Energy Transfers
  4. Magnetism Practice Questions: Induction and Energy Transfers. Test and improve your knowledge of Induction and Energy Transfers with example questins and answers
  5. Check your calculations for Magnetism questions with our excellent Magnetism calculators which contain full equations and calculations clearly displayed line by line. See the Magnetism Calculators by iCalculator™ below.
  6. Continuing learning magnetism - read our next physics tutorial: Induced Electric Fields

Help others Learning Physics just like you

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

★★★★★ [ 1 Votes ]

We hope you found this Physics lesson "Induction and Energy Transfers" useful. If you did it would be great if you could spare the time to rate this physics lesson (simply click on the number of stars that match your assessment of this physics learning aide) and/or share on social media, this helps us identify popular tutorials and calculators and expand our free learning resources to support our users around the world have free access to expand their knowledge of physics and other disciplines.

Magnetism Calculators by iCalculator™

© iCalculator™ 2009 - 2024 | Physics Calculators | Privacy Policy | Terms of Use | Contact