A copper wire of length 25 cm is in a magnetic field of 0.20 T.If it has a mass of 10 g,what is the minimum current through the wire that would cause a magnetic force equal to its weight?

Question

Quizplus · Accepted Answer

The magnetic force on a current-carrying wire in a magnetic field is given by:

F = BIL

where F is the magnetic force, B is the magnetic field, I is the current, and L is the length of the wire in the magnetic field.

We want to find the minimum current that will produce a magnetic force equal to the weight of the wire. The weight is given by:

W = mg

where W is the weight, m is the mass, and g is the acceleration due to gravity.

Setting these two expressions equal, we have:

BIL = mg

Solving for I, we get:

I = mg/BL

Plugging in the given values, we get:

I = (0.01 kg)(9.8 m/s^2)/(0.2 T)(0.25 m) = 2.0 A

Therefore, the minimum current that will produce a magnetic force equal to the weight of the wire is 2.0 A, which corresponds to choice C.

A Copper Wire of Length 25 Cm Is in a Magnetic