Practice Faraday's Law in Physics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The induced EMF in a circuit equals the negative rate of change of magnetic flux through the circuit.
The faster you change the magnetic field through a loop, the bigger the voltage you get. Faraday's law tells you exactly how much.
Example 1
mediumA coil with 100 turns experiences a change in magnetic flux from 0.05 \text{ Wb} to 0.02 \text{ Wb} in 0.1 \text{ s}. What is the induced EMF?
Example 2
hardA single loop of area 0.04 \text{ m}^2 is in a magnetic field that increases uniformly from 0 to 0.6 \text{ T} in 0.3 \text{ s}. What is the induced EMF?
Example 3
mediumA coil of 50 turns has an area of 0.01 \text{ m}^2. The magnetic field through it decreases from 0.8 \text{ T} to 0.2 \text{ T} in 0.5 \text{ s}. What is the average induced EMF?
Example 4
mediumA coil of 50 turns has a magnetic flux that changes from 0.02 \text{ Wb} to 0.08 \text{ Wb} in 0.1 \text{ s}. Find the induced EMF.
Example 5
hardA square coil with 200 turns and side length 0.1 \text{ m} is in a magnetic field that decreases uniformly from 0.5 \text{ T} to 0 \text{ T} in 0.2 \text{ s}. Calculate the induced EMF. In which direction does the induced current flow (clockwise or anticlockwise, if the field points into the page)?