Answer:
Here is the complete question:
https://www.chegg.com/homework-help/questions-and-answers/magnetic-field-372-t-achieved-mit-francis-bitter-national-magnetic-laboratory-find-current-q900632
a) Current for long straight wire 
b) Current at the center of the circular coil 
c) Current near the center of a solenoid 
Explanation:
⇒ Magnetic Field due to long straight wire is given by (B),where

Plugging the values,
Conversion
,and 

⇒Magnetic Field at the center due to circular coil (at center) is given by,
So 
⇒Magnetic field due to the long solenoid,
Then
So the value of current are
,
and
respectively.
Answer:
Explanation:
The "traditional" form of Coulomb's law, explicitly the force between two point charges. To establish a similar relationship, you can use the integral form for a continuous charge distribution and calculate the field strength at a given point.
In the case of moving charges, we are in presence of a current, which generates magnetic effects that in turn exert force on moving charges, therefore, no longer can consider only the electrostatic force.
Answer:
B. w=12.68rad/s
C. α=3.52rad/s^2
Explanation:
B)
We can solve this problem by taking into account that (as in the uniformly accelerated motion)
( 1 )
where w0 is the initial angular speed, α is the angular acceleration, s is the arc length and r is the radius.
In this case s=3.7m, r=16.2cm=0.162m, t=3.6s and w0=0. Hence, by using the equations (1) we have


to calculate the angular speed w we can use
Thus, wf=12.68rad/s
C) We can use our result in B)

I hope this is useful for you
regards
A.) Hertz is the measuring unit for frequency!!
[Your explanation is correct]
Hope this helps!