Answer:
a) 
Explanation:
Given paraeters are:
R = 25 cm
d = 4.7 mm
f = 60 Hz
= 160 V
a) 
Where
Hz and
V

For 

Since 

From Ampere's Law:
where 
So at
,

For maximum B, cos(2πft) = 1. Hence,
T
b) From r = 0 to r = R = 0.025 m, by Ampere's Law, the equation will be:

From r = R = 0.025 m to r = 0.1 m, by Ampere's Law, the equation will be:

The plot is given in the attachment.
The Earth and the Moon circle their common center of mass, and
that common center of mass is what circles the Sun, once a year.
10 mph i jus got it right on the test
I believe the answer is 40,000 Hz to 100,000 Hz
Is there a picture so I can help you