PHYS 2212 Module 9.4

Induced Electric Fields

Recommended Reading

9.4 Induced Electric Fields

Learning Objectives

By the end of this section, you will be able to:

  • Connect the relationship between an induced emf from Faraday’s law to an electric field, thereby showing that a changing magnetic flux creates an electric field
  • Solve for the electric field based on a changing magnetic flux in time

Induced Electric Fields


Practice 9.4.1
An electric field of 4.0 µV/m is induced at a point 2.0 cm from the axis of a long solenoid (radius = 3.0 cm, 800 turns/m). At what rate is the current in the solenoid changing at this instant?
Check your answer: B. 0.40 A/s
Practice 9.4.2
A long solenoid has a radius of 2.0 cm and has 700 turns/m. If the current in the solenoid is decreasing at the rate of 8.0 A/s, what is the magnitude of the induced electric field at a point 2.5 cm from the axis of the solenoid?
Check your answer: A. 56 µV/m