The magnetic field inside a toroid is uniform.
a. true
b. false

The concept that must be applied to solve this problem is that of the magnetic field on Toroid described since the law of Ampere. Mathematically the magnetic field is determined as

Where

= Permeability constant

N = Number of loops

I = Current

r = Radius

As we can see the magnetic field inside a Toroid is NOT uniform, since it is highly proportional to the radius. Which means that as the radius increases the magnetic field decreases.

Therefore the correct answer is: FALSE

d. platinum would have the greatest temperature increase because it has the lowest specific heat.