See for yourself how the forces of electricity and magnetism can work together by building a simple DC electric motor using simple materials you can find in any hardware store!
Electricity and magnetism are both forces caused by the movement of tiny charged particles that make up atoms, the building blocks of all matter. When a wire is hooked up to a battery, current flows through the wire because negatively charged electrons flow from the negative terminal of the battery toward the positive terminal of the battery because opposite charges attract each other, while similar charges repel each other. This flow of electrons through the wire is an electric current, and it produces a magnetic field.
In a magnet, atoms are lined up so that the negatively charged electrons are all spinning in the same direction. Like an electric current, the movement of the electrons creates a magnetic force. The area around the magnet where the force is active is called a magnetic field. Metal objects and other magnets that enter this field will be pulled toward the magnet.
The way the atoms are lined up creates two different poles in the magnet, a north pole and a south pole. As with electrical charges, opposite poles attract each other, while like poles repel each other.
Learn about electromagnetism and its many uses here.
Now let's watch it work as we build a motor.
(Note: This science project requires adult supervision.)
Answer:
Faraday's law
, he direction of the magnetic field changes by 180º, in the polarity inversion processes, induces a voltage.
Explanation:
For this exercise let's use Faraday's law
E = - dФ / dt
Ф = B.A = B A cos θ
where B is the magnetic field, A is the area and θ is the angle between the field line and the normal to the area.
We can see that an electromotive force (voltage) is indexed when there is a variation of the field B, a variation of the area and change of the angle or when there is a combinational of them.
In this case, the magnitude of the field is constant, as the wire is rigid metal, the area is constant, but the direction of the magnetic field changes by 180º, in the polarity inversion processes, for which reason each change induces a voltage.
If a voltage is created in the ring, which has a resistance, a current is also generated in it.
Therefore the answer is If a current is created in the hoop
<span>These Russian nesting dolls are a good analogy for the strongest magnet in the world, because the magnitis were put inside each other. The magnets would be fitted together. Because they are closer together, the coils of magnet would be stronger. They would be able to magnetize better.</span>
1km=10^3 m,1km^3=10^9cubic metres answer is 1.4x10^18cubic meters
Work with your units:
1 watt-hour = 1 (joule/second) · (hour) = 1 (joule-hour / second)
(1 joule-hour/sec) · (3600 sec/hour) = 3600 joules
So 1 watt-hour = 3,600 joules
