How can a strong electromagnetic wave be generated and received by it 15

Characteristics of electromagnetic waves:

a.Electromagnetic waves propagate in all directions in space;

b.No medium is required for the propagation of electromagnetic waves. But electromagnetic waves can propagate in air, water, certain solids;

c.The propagation speed of electromagnetic waves is equal to the speed of light, and the propagation speed in air and in a vacuum is similar;

d.Electromagnetic waves of different frequencies (or different wavelengths) travel at the same speed, so the shorter the wavelength of electromagnetic waves, the higher the frequency; Conversely, the frequency is lower.

Mercury rotates at high speeds and can generate huge electromagnetic fields that can even counteract gravity. During World War II, Germany used mercury flow engines to build dish-shaped aircraft, but the technical details were difficult. Hope to adopt.

How strong you want to be strong, thunder and lightning, solar flares.

There are two processes of transmitting and receiving electromagnetic waves.

1) The emission process of electromagnetic waves.

Principle: The work of using electromagnetic waves to send sound and image signals is undertaken by radio and television stations, oscillations in radio stations.

The device first generates a high-frequency oscillating current, and at the same time changes the sound signal into an electrical signal, which is loaded onto the radio wave by the modulator, and emitted into the air through the antenna of the transmitter.

Oscillator: A device that generates a high-frequency oscillating current.

Modulator: A device that converts a high-frequency oscillating current into a high-frequency oscillating current with a signal.

2) The process of receiving electromagnetic waves.

Principle: The reception of sound is done by the radio, and the receiving antenna of the radio receives the electromagnetic waves carrying the signal in the air.

After the tuner processed, the electrical signal of the sound was taken out by the detector, and the electrical signal was restored to sound by the speaker.

Tuner: It is a device that selects a certain frequency of electromagnetic waves from many frequencies and turns it into an electric current.

Geophone: A device that extracts a sound signal from a high-frequency oscillating current.

Summary. Insulators can transmit electromagnetic waves, good conductors can reflect electromagnetic waves, and resistors can allow electromagnetic waves to enter and continuously consume their energy.

For example, in a microwave oven, air can pass through microwaves, the metal shell can reflect and block microwaves, and the heated water can absorb and consume microwave energy and convert it into heat to make the water temperature rise.

What can hinder the transmission of electromagnetic waves, and what can absorb electricity.

Insulators can transmit electromagnetic waves, good conductors can reflect electromagnetic waves, and resistors can allow electromagnetic waves to enter and continuously consume their energy. For example, in a microwave oven, air can pass through microwaves, the metal shell can reflect and block microwaves, and the heated water can absorb and consume microwave energy and convert it into heat to make the water temperature rise.

The substance that absorbs the most electromagnetic radiation is metal, and the most effective barrier to electromagnetic radiation is lead.

Electromagnetic interference can also be used to block external electromagnetic waves.

You can refer to it.

Hope it helps.

This one. Empty place.

Okay. I don't know what to fill in.

Metal. It can be shielded and absorbed.

Do both fill with metal.

OK. Electromagnetic field shielding is the use of shielding to prevent electromagnetic fields from propagating in space. Electromagnetic field shielding is done by the reflection and absorption of electromagnetic waves, and the shielding effect is independent of the thickness of the shield, which is different from electric field shielding and magnetic field shielding.

Electromagnetic waves are produced by the constant change of electric current

The radio can receive electromagnetic waves, use a wire to short-circuit the battery, and use the wire to rub constantly at any pole of the battery, and the current will constantly change, which will produce electromagnetic waves The radio receives irregular electromagnetic waves, and there is noise

Therefore, the answer is: use a wire to short-circuit the battery, and use the wire to rub constantly at any pole of the battery; near an open radio; If there is a noise, it proves the presence of electromagnetic waves

In order to effectively emit tremor electromagnetic waves to the outside world, the oscillation circuit must have the following characteristics:

First, it is necessary to have a sufficiently high oscillation frequency The study of the theory proves that the ability of the oscillating circuit to radiate energy to the outside world, that is, the energy radiated out per unit time, is proportional to the fourth degree of frequency The higher the frequency, the greater the ability to emit electromagnetic waves

Second, the electric and magnetic fields of the oscillating circuit must be dispersed into as large a space as possible, and an open circuit must be used to effectively propagate the energy of the electromagnetic field

Therefore, in order to emit radio waves, it is necessary to modify the LC oscillation circuit to increase the distance between the capacitor plates, reduce the area of the plates, and reduce the number of turns of the self-inductance coil, so as to reduce the values of L and C, increase the oscillation frequency, and at the same time expand the electric and magnetic fields into the outer space Such an oscillation circuit is called an open circuit Finally, the open circuit can even evolve into a wire that can effectively emit electromagnetic waves from the open circuit

So the answer is: high enough; open circuits; Ground; Antenna.

The generation of electromagnetic waves, the family of electromagnetic waves, the discovery of electromagnetic waves, the strength of electromagnetic waves.