Question

Write 250 words.

Question: Theory -- Here, provide the relevant theoretical background including all formulas needed for the analysis. Make sure you define the different quantities and symbols that you have used in your report.

lab:

http://phys205r1.athabascau.ca/lab-manual/phys205-lab-exp4.html

Answer 1

Solenoid is a device that creates large magnetic field. Several turns of wire closely wound over a cylinder, when current pass through such arrangement, magnetic field is produced. Now, since each turn of wire (nearly circular) creates magnetic field, and there are thousands of turns. Also, each turn carries current in the same direction, so each turn produces magnetic field in the same direction, and hence total magnetic field is quite large.

Now, magnetic field due to the solenoid is given as

where,

: permeability of free space

n: number of turns per unit length

I: current that passes through

For ideal solenoid, we take field inside as parallel to the solenoid axis (that is cylindrical axis), and also zero field outside the solenoid.

For real solenoid, field inside is not exactly parallel to the axis, it is somewhat curved near the ends. And, some field exists outside too.

The magnetic field lines of a solenoid are very similar to that of a bar magnet.