Question

Question #ac43a

Answer 1

The equation describing the strength of the magnetic field inside a solenoid is:

`B = mu_0 * i * N/L`

`B` is the magnetic field.
`mu_0` is the permeability of free space (also known as the magnetic constant)
`i` is the electric current
`N` is the number of wire turns in the solenoid
`L` is the length of the solenoid

Take a step back and look at the equation to see what things we might change to make `B` larger.

• Making `i` larger would result in a larger field.
• Adding more turns to the coil would increase `N` and result in a larger field.
• Making `L` smaller by, for example, squishing the long tube into a short donut shape, would result in a larger field.

Just to annoy your physics teacher, you might also suggest changing the magnetic constant by radically altering the nature of the universe itself. We don't know how to do this, but that doesn't stop us from making a theoretical prediction of how this would change the strength of the magnetic field. It is possible to add a material other than just free space inside the solenoid. Iron, for example, has a different permeability and would result in a higher field strength.