Electricity & Megnetism
Inductance of a toroid formula derivation and examples
What is toroid?
The solenoid bent into a circular shape is called a toroid.
Inductance of a toroid derivation
Consider a toroid having a rectangular cross-sectional area. The inner radius of the toroid is ‘a’ while the outer radius is b. The number of turns of the toroid is N. Let I will be the current flowing through each turn of the toroid. The magnetic field lines inside the solenoid are given as:
Where dA = hdr is the area of the elementary strip of the toroid. Putting the value of ‘B’ from equation (1) we get:
Which is the relation for the inductance of solenoid. The inductance L depends only on geometrical factors.