Question

How does doubling number of turns in a toroidal coil affect the value of magnetic flux density ?

• A. Four times
• B. Eight times
• C. Half
• D. Double

Answer 1

The correct option is D Double

Magnetic field due to a toroidal coil of radius r having n turns and carrying a current i is given by:
$B={\mu }_{0}ni/2\pi r$. So B is proportional to n. If we doubled the number of turns then the field will be also doubled.