Question

A solenoid of length 1.5 m and 4 cm diameter possesses 10 turns per cm. A current of 5A is flowing through it, the magnetic induction at axis inside the solenoid is $({\mu }_0=4\pi \times {10}^{-7}weberam{p}^{-1}{m}^{-1})$

• A. $4\pi \times {10}^{-5}gauss$
• B. $2\pi \times {10}^{-5}gauss$
• C. $4\pi \times {10}^{-5}tesla$
• D. $2\pi \times {10}^{-5}tesla$

Answer 1

The correct option is D $2\pi \times {10}^{-5}tesla$

$B={\mu }_{0}nI=4\pi \times {10}^{-7}\times 10\times 5=2\pi \times {10}^{-5}T$.