Question

A long solenoid has magnetic field strength of $3.14\times {10}^{-2}T$ inside it when a current of $5A$ passes through it. The number of turns in $1m$ of the solenoid is

• A. 1000
• B. 3000
• C. 5000
• D. 10000

Answer 1

Answer: (C)

5000

No of turns per unit length for an infinite solenoid: $n=\frac{B}{{\mu }_{0}i}=\frac{3.14\times {10}^{-2}}{4\pi \times {10}^{-7}\times 5}=5000$