The Electromagnetic Levitating Ring · AI Generator #GEN-C9FEF697
Physics · electromagnetism
Problem
A horizontal circular conducting ring of radius R=5.0cm, mass m=12g, and resistance ρ=0.15Ω is placed above a solenoid coil. The solenoid has N=800 turns, radius r=3.0cm, and height h=6.0cm. The ring is positioned so that its center is directly above the center of the solenoid at a height d=4.0cm above the solenoid's top face.
When an alternating current I(t)=I0sin(ωt) with amplitude I0=8.0A and angular frequency ω=2π×60Hz flows through the solenoid, the ring experiences a time-averaged upward magnetic force that exactly balances its weight, causing it to levitate.
(a) Find the magnetic flux Φ(t) through the ring as a function of time.
(b) Calculate the time-averaged power dissipated in the ring due to the induced current.
(c) Determine the time-averaged magnetic force on the ring and verify that it equals the gravitational force.
Use g=9.8m/s2, μ0=4π×10−7H/m.