A coil of radius 5cm has 98 closely wound turns of a metal wire. Magnetic field of strength$ 6.2 \times 10^{-3}T$ is produced at the centre of this coil, when a current of 5.2 A is passes through it.Magnetic field of same strength is to be produced at the centre of another coil with 10cm radius. select the correct possible way to do so.
Answer & explanation
Correct answer: option 1
$ B = \frac{\mu_0 NI}{2 R} $
$\text{Magnetic Field is propotional to }\frac{NI}{R}$
$\text{Correct option is 2}$