Question

A circle having $100$ turns has a current of $4A$ flowing through it.It is necessary to have a magnetic field of induction $\pi \times {10}^{-5}$ T at the centre. The radius of the circle must be

• A. $0.08cm$
• B. $0.8cm$
• C. $8m$
• D. $80cm$

Answer 1

The correct option is C $8m$

Question can be solved by formula of magnetic field at the center of circle.