The formula for the energy stored in the magnetic field of an inductor is:
E = (1/2) (inductance) (current)² .
In the present situation:
Energy = (3 kilo-watt-hour) x (1,000 / kilo) x (joule/watt-sec) x (3,600 sec/hr)
= (3 · 1000 · 3,600) (kilo·watt·hr·joule·sec / kilo·watt·sec·hr)
= 1.08 x 10⁷ joules .
Now to find the inductance:
E = (1/2) (inductance) (current)²
(1.08 x 10⁷ joules) = (1/2) (inductance) (300 Amp)²
(2.16 x10⁷ joules) = (inductance) (300 Amp)²
Inductance = (2.16 x10⁷ joules) / (300 Amp)²
= 2.16 x10⁷ / 90,000 Henrys
I get 240 Henrys .
This is a big inductance. Possibly the size of your house.
To get a big inductance, you want to wind the coil
with a huge number of turns of very fine wire, in
a small space.
In this case, however, if you plan on running 300A through
your coil, it'll have to be wound with a very thick conductor ...
like maybe 1/4-inch solid copper wire, or even copper tubing,
You have competing requirements.
There are cheaper, easier, better ways to store 3 kWh of energy.
In fact, a quick back-of-the-napkin calculation says that
3 or 4 car batteries will do the job nicely.
Nothing has to turn.
Sunlight <u><em>IS</em></u> solar energy !
Answer:
A. Ein = 8.05*10^-4 V/m
B. Clockwise sense
Explanation:
A. the magnitude of the electric field induced in the ring is obtaind by using the following formula:
(1)
Ein: induced electric field
ds: differential of a path of the ring
ФB: magnetic flux in the ring
The Ein vector is parallel to ds in the complete ring. Furthermore, the area of the ring is constant, hence, you have in the equation (1):
(2)
dB/dt = -0.280T/s (it is decreasing)
A: area of the ring = π(r/2)^2= (π/4) r^2
r: radius of the ring = 4.60/2 = 2.30 cm
Then, you replace the values of all variables in the equation (2):
hence, the induced electric field is 8.05*10^-4 V/m
B. The induced current in the ring produced a magnetic field that is opposite to the magnetic field of the magnet. The, in this case you have that the induced current is in a clockwise sense.
Based on the description, it will be most likely that he believes in Oscillating model (also known as Cyclic model) of the universe
Based on this model, the gravitational force will prevent further expansion by pulling back the matters and undergo a bounce
hope this helps
