Answer:
The maximum value of the induced magnetic field is
.
Explanation:
Given that,
Radius of plate = 30 mm
Separation = 5.0 mm
Frequency = 60 Hz
Suppose the maximum potential difference is 100 V and r= 130 mm.
We need to calculate the angular frequency
Using formula of angular frequency

Put the value into the formula


When r>R, the magnetic field is inversely proportional to the r.
We need to calculate the maximum value of the induced magnetic field that occurs at r = R
Using formula of magnetic filed

Where, R = radius of plate
d = plate separation
V = voltage
Put the value into the formula


Hence, The maximum value of the induced magnetic field is
.
B) All nonzero digits are significant.
Answer:
a)
b)
Explanation:
The energy density is "the energy per unit volume, in the electric field. The energy stored between the plates of the capacitor equals the energy per unit volume stored in the electric field times the volume between the plates".
A magnetic field is a "vector field that describes the magnetic influence of electric charges in relative motion and magnetized materials".
Part a
For this case we can assume use the equation for the magnetic field in terms of the energy per unit of volume.

Where μ0 represent the permeability constant, also known as the magnetic constant. If we solve for u we got:

We also know that the magnetic field can be expressed in terms of the current and the radius of action R like this:

Replacing this on the formula for u we have:

And simplyfing we got:

Replacing the values given we have:

Part b
The density current is given by this formula
and the resistance by 
If we use the equation for the energy density we have this:

And replacing the values given we have:

Answer:
it depends most of the time but i don't really have a clue either
Answer:
18301.4Kg
Explanation:
Step 1:
Data obtained from the question. This include the following:
Mass 1 (M1) = 0.512Kg
Mass 2 (M2) =..?
Distance apart (r) = 0.0250m
Force (F) = 0.001N
Gravitational force constant (G) = 6.67x10^-11Nm²/Kg²
Step 2:
Determination of the mass, M2 needed to create a force of 0.001N.
This can be obtained as follow:
F = GM1M2/r²
0.001 = 6.67x10^-11 x 0.512 xM2/0.025²
Cross multiply
6.67x10^-11 x 0.512 xM2 = 0.001x0.025²
Divide both side by 6.67x10^-11 x 0.512
M2 = (0.001x0.025²)/(6.67x10^-11x0.512)
M2 = 18301.4Kg
Therefore, a mass of 18301.4Kg is needed