3 A 110 m long straight wire has a resistance R 390 ohm and

3.

A 1.10 m long straight wire has a resistance R = 39.0 ohm and is connected to a 1.50 V battery. The wire is located in a uniform magnetic field B directed perpendicular to the wire. Calculate the magnitude of B when the force on the wire due to B is 0.240 N.

Solution

given

voltage = 1.5 v

resistance = 39 ohm

so I = V/R = 1.5/39 = 0.0384  amp.

we know that

B = F/iL

so

B =  0.240 / 0.0384*1.10

= 6.87 T