A current with a force of I = 2.5 A passes along a horizontal wire with a length of l = 40 cm and a mass of m = 4.0 g

A current with a force of I = 2.5 A passes along a horizontal wire with a length of l = 40 cm and a mass of m = 4.0 g. Determine the induction B of the magnetic field in which the wire must be placed so that it hangs without falling.

To solve the presented problem, we write down the formula for finding the magnetic induction force, which connects the magnetic induction force, current strength and conductor length:

F = BIL,

where B is the magnetic induction;

I is the current strength;

L is the length of the conductor.

Hence, the magnetic induction B is equal to:

B = F / IL

To find the force of magnetic induction, it is not enough just to find the value of the force F. It can be calculated from the formula for the force of gravity:
F = mg = 4 g * 10 N / kg = 0.004 kg * 10 N / kg = 0.04 N.

Substituting the force into the formula for magnetic induction, we get:
B = 0.04 / 2.5 * 0.4 = 0.04 T.

Answer: 0.04 T.