A solenoid of 1.5 metre length and 4.0 cm diameter posses 10 turn per cm. A current of 5 ampere is flowing through it. The magnetic induction at axis inside the solenoid is

Options

A. `2PI xx10^(-3) t`
B. `2OIxx10^(-5)t`
C. `2PI xx10^(-3) g`
D. `2PIxx10^(-5)g`

Explanation

Given length l=15 m
number of turns n = 10 turns / cm
current I =5A
magnetic field inside the solenoid B= `mu_(0)ni`
`=4 pi xx10^(-7)xx5xx1000=2pi lkxx10^(-3)T`