Answer:
Mutual inductance, 
Explanation:
(a) A toroidal solenoid with mean radius r and cross-sectional area A is wound uniformly with N₁ turns. A second thyroidal solenoid with N₂ turns is wound uniformly on top of the first, so that the two solenoids have the same cross-sectional area and mean radius.
Mutual inductance is given by :

(b) It is given that,


Radius, r = 10.6 cm = 0.106 m
Area of toroid, 
Mutual inductance, 

or

So, the value of mutual inductance of the toroidal solenoid is
. Hence, this is the required solution.
340 ms
I got it right and I hope you do as well
The correct answer is going to be <span>C, because in the nucleus of an atom there are protons and electrons; which can't move, and are surrounded by electrons on the electrical cloud</span>