Question

You have a 9-V battery, a set of 10 50-Ω resistors, and a long (2-m ) connecting wire. Take the thickness of the wire to be 0.6 mm and the radius of solenoid to be 1 cm .

Estimate the maximum magnitude of the B→ field that you can produce with this equipment.

Answer 1

when, 10 and 50 ohms are connected in parallel, net resistance will be less and more current

Rnet = 10*50/(10+50)

= 8.33 ohms

flows through the solenoid and we get maximum magnetic field.

no of turns, N = length of the wire/(2*pi*r)

= 2/(2*pi*0.01)

= 32

length of the solenoid, L = N*t

= 32*0.6 mm

= 19.2 mm

= 0.0192 m

current through solenoid, I = V/Rnet

= 9/8.33

= 1.08 A

so, maximum magnetic field through solenoid, Bmax = mue*N*I/L

= 4*pi*10^-7*32*1.08/0.0192

= 2.26*10^-3 T <<<<<<<<<---------Answer