Question

Magnetic field inside the turns of a toroid is

• A. Variable
• B. $0$
• C. Constant
• D. $\infty$

Answer 1

The correct option is A Variable

Let the toroid be as above with a,r,b as internal radius, toroid radius and outer radius and current is I.

Now the magnetic field can be calculated by Ampere's law as below:

$B2\pi r=\mu NI$

Where B= magnetic field, N= number of turns

$⟹B=\frac{\mu NI}{2\pi r}$

Here, $B\propto \frac{1}{r}$

Thus magnetic field inside the turns of toroid is variable.