A thin copper rod 1.0 m long has a mass of 0.050 kg and is in a $\vec { B }$ field of 0.10 T.What minimum current in the rod is needed in order for the magnetic force to balance the force exerted on the rod by Earth?

Question

Quizplus · Accepted Answer

The magnetic force $ F_B $ on the rod is given by $ F_B = I \cdot L \cdot B $, where $ I $ is the current, $ L $ is the length of the rod, and $ B $ is the magnetic field. The gravitational force $ F_g $ is $ m \cdot g $, where $ m $ is the mass and $ g $ is the acceleration due to gravity (approximately 9.8 m/s²). Setting $ F_B = F_g $, we get $ I \cdot 1.0 \cdot 0.10 = 0.050 \cdot 9.8 $. Solving for $ I $, we find $ I = 4.9 $ A.

A Thin Copper Rod 1 B⃗\vec { B }B Field of 0

A Thin Copper Rod 1 $\vec { B }$ Field of 0