Magnetic Effects of Current and Magnetism Part 3

A tightly wound long solenoid carries a current of 1.5 A. An electron is executing uniform circular motion inside the solenoid with a time period of 75 ns. The number of turns per metre in the solenoid is _____
[Take mass of electron me=9×10−31‌kg, charge of electron qe|=1.6×10−19C, µ0=4π×10−7‌

N

A2

,1‌ns=10−9 s]