To solve this problem it is necessary to apply the concepts related to mutual inductance in a solenoid.
This definition is described in the following equation as,

Where,
permeability of free space
Number of turns in solenoid 1
Number of turns in solenoid 2
Cross sectional area of solenoid
l = Length of the solenoid
Part A )
Our values are given as,





Substituting,



PART B) Considering that many of the variables remain unchanged in the second solenoid, such as the increase in the radius or magnetic field, we can conclude that mutual inducantia will appear the same.
Answer:
Doppler Theory
Explanation:
it's a theory regarding the change in wave frequency during the relative motion between a wave source and its observer.
Over time, yes. It will over time gain more momentum
Answer:
Acceleration, 
Explanation:
It is given that,
Separation between the protons, 
Charge on protons, 
Mass of protons, 
We need to find the acceleration of two isolated protons. It can be calculated by equating electric force between protons and force due to motion as :


So, the acceleration of two isolated protons is
. Hence, this is the required solution.