# Exploring electromagnetism! 2!

**Electricity and Magnetism**Level 5

A thin ring wire of radius a and resistance \(r\) is placed coaxially inside a long solenoid of length l and cross-sectional radius \(b \). at \(t= 0\) the solenoid is connected to a battery of emf \(V \). If total circuit resistance is R find the maximum magnetic radial force per unit length acting on the ring wire.

All given values are in SI Units

Assume that current in the ring is the Induced current in accordance to Lenz's law and faraday's law only . no current flowing through the solenoid enters the ring

The solenoid can be taken as an ideal inductor in this case

Neglect the after effects of Induced electric field due to time-varying magnetic fields in this case

The solenoid is infinitely long and magnetic field can be taken as constant throughout the axis of solenoid

Take \(a=10, b = 20, V= 10, R = 10, r = 10, l = 10 \).

Multiply your answer by \(10^9\).

Neglect Mutual Inductance between ring and inductor

Round off answer to 3 decimals.