Now let's move on to the consideration of the properties and characteristics of electromagnetic waves. One of the characteristics of electromagnetic waves is the density electromagnetic radiation.
Consider a surface with an area S through which electromagnetic waves carry energy.
The electromagnetic radiation flux density I is the ratio of electromagnetic energy Wpassing in time t through a surface perpendicular to the rays with an area S, to the product of the area S and time t.
The radiation flux density, in SI, is expressed in watts per square meter(W / m 2). Sometimes this quantity is called the intensity of the wave.
After a series of transformations, we get that I = w c.
i.e., the density of the radiation flux is equal to the product of the density of electromagnetic energy and the speed of its propagation.
We have repeatedly met with the idealization of real sources of acceptance in physics: material point, ideal gas, etc. Here we will meet another one.
A radiation source is considered to be a point source if its dimensions are much smaller than the distance at which its effect is estimated. In addition, it is assumed that such a source sends electromagnetic waves in all directions with the same intensity.
Let us consider the dependence of the radiation flux density on the distance to the source.
The energy that electromagnetic waves carry with them is distributed over a larger and larger surface over time. Therefore, the energy transferred through a unit area per unit time, i.e., the radiation flux density, decreases with distance from the source. It is possible to find out the dependence of the radiation flux density on the distance to the source by placing a point source in the center of a sphere with a radius R. the surface area of the sphere S= 4 n R^2. If we assume that the source in all directions during the time t radiates energy W
The radiation flux density from a point source decreases in inverse proportion to the square of the distance to the source.
Let us now consider the frequency dependence of the radiation flux density. As you know, the radiation of electromagnetic waves occurs during the accelerated movement of charged particles. tension electric field and magnetic induction electromagnetic wave proportional to acceleration a emitting particles. Acceleration at harmonic vibrations proportional to the square of the frequency. Therefore, the electric field strength and magnetic induction are proportional to the square of the frequency
The energy density of the electric field is proportional to the square of the field strength. Energy magnetic field proportional to the square of the magnetic induction. Total energy density electromagnetic field is equal to the sum of the energy densities of the electric and magnetic fields. Therefore, the radiation flux density is proportional to: (E^2+B^2). From here we get that I is proportional to w^4.
Topics of the USE codifier: properties of electromagnetic waves, different kinds electromagnetic radiation and their application.
The most important result of electrodynamics, which follows from Maxwell's equations (this is not the first time we are talking about Maxwell's equations, but we do not write out the equations themselves. There's nothing to be done - these equations are still too complicated for you. You will get acquainted with them in the second year, when they are mastered necessary topics from higher mathematics), is that electromagnetic interactions are transmitted from one point of space to another not instantly, but at a finite speed. In vacuum, the speed of propagation of electromagnetic interactions coincides with the speed of light m/s.
Consider, for example, two charges at rest, located at some distance from each other. The strength of their interaction is determined by Coulomb's law. Move one of the charges; according to Coulomb's law, the interaction force will change instantly - the second charge will immediately "feel" the change in the position of the first charge. This was stated by the theory of long-range action (the theories of long-range and short-range action were discussed in the leaflet "Intensity of the electric field").
However, in reality the situation is different. When the charge moves electric field near it changes and generates a magnetic field. This magnetic field is also variable, in turn, generates an alternating electric field, which again generates an alternating magnetic field, and so on. In space, the process of fluctuations in the strength of the electric field and the induction of the magnetic field begins to spread - an electromagnetic wave. After some time, this electromagnetic wave will reach the second charge; only then - and not instantly! - he will “feel” that the position of the first charge has changed.
The existence of electromagnetic waves was predicted by Maxwell and received brilliant confirmation in the experiment of Hertz.
Hertz experiment: open oscillatory circuit
Electromagnetic waves must be strong enough to be observed experimentally.
It is easy to understand that electromagnetic waves will be the more intense, the faster the position of the charges emitting these waves changes. Indeed, in this case, the electric field near the charges changes at a faster rate and generates a larger magnetic field; it, in turn, changes just as quickly and generates a larger electric field, and so on.
In particular, intense electromagnetic waves are generated by high-frequency electromagnetic oscillations.
Electromagnetic oscillations are created in an oscillatory circuit that is well known to us.
The frequency of charge and current oscillations in the circuit is equal to:
(1)
The vectors oscillate with the same frequency at a given point in space. Thus, the value calculated by formula (1) will also be .
To increase the frequency of oscillations in the circuit, it is necessary to reduce the capacitance of the capacitor and the inductance of the coil.
But experiments have shown that the matter is not limited to high frequency oscillations alone. For the formation of intense electromagnetic waves, another factor is essential: an alternating electromagnetic field, which is a source of electromagnetic waves, must occupy a sufficiently large area of space.
Meanwhile, in an ordinary oscillatory circuit consisting of a capacitor and a coil, the alternating electric field is almost entirely concentrated in a small area inside the capacitor, and the alternating magnetic field is concentrated in a small area inside the coil. Therefore, even at a sufficiently high oscillation frequency, such an oscillatory circuit turned out to be unsuitable for the emission of electromagnetic waves.
How to achieve an increase in the area occupied by a high-frequency electromagnetic field? Hertz found a beautiful and ingeniously simple solution - open oscillatory circuit.
Let's take an ordinary oscillatory circuit (Fig. 1, left). Let's start to reduce the number of turns of the coil - from this its inductance will decrease. At the same time, we reduce the area of the capacitor plates and move them apart - this leads to a decrease in the capacitance of the capacitor and to an increase in the spatial area occupied by the electric field. This intermediate situation is shown in Fig. 1 in the middle.
Rice. 1. The transformation of a conventional oscillatory circuit into an open one
What will we come to by continuing this process? The coil is completely eliminated, turning into a piece of conductor. The plates of the capacitor move as far as possible and end up at the ends of this conductor (Fig. 1, right). It remains to reduce the dimensions of the plates to the limit - and you get the most ordinary straight rod! This is an open oscillatory circuit (Fig. 2).
Rice. 2. Open oscillatory circuit
As you can see, Hertz's idea of an open oscillatory circuit made it possible to "kill two birds with one stone":
1) the capacitance and inductance of the rod are very small, therefore, oscillations of a very high frequency are excited in it; 2) an alternating electromagnetic field occupies a rather large area of space around the rod.
Therefore, such a rod can serve as a source of sufficiently intense electromagnetic waves.
But how to excite electromagnetic oscillations in the rod? Hertz cut the rod in the middle, pushed the halves apart a short distance (creating the so-called discharge gap) and connected them to a high voltage source. It turned out Hertz radiating vibrator(Fig. 3; the ends of the wire in the discharge gap were supplied with small balls).
Rice. 3. Radiating Hertz vibrator
When the voltage between the balls exceeded the breakdown voltage, a spark jumped in the discharge gap. During the existence of a spark, the circuit was closed, and electromagnetic oscillations arose in the rod - the vibrator emitted electromagnetic waves.
Hertz recorded these waves using receiving vibrator- a conductor with balls at the ends of the discharge gap (Fig. 4). The receiving vibrator was at some distance from the emitting vibrator.
Rice. 4. Hertz receiving vibrator
The alternating electric field of the electromagnetic wave excited in the receiving vibrator alternating current. If the frequency of this current coincided with the natural frequency of the receiving vibrator, then a resonance arose, and a spark jumped in the discharge gap!
The presence of this spark, appearing at the ends of a completely insulated conductor, was a clear indication of the existence of electromagnetic waves.
Properties of electromagnetic waves
For the emission of electromagnetic waves, the charge does not have to be oscillating motion; the main thing is that the charge has acceleration. Any charge moving with acceleration is a source of electromagnetic waves. In this case, the radiation will be the more intense, the greater the charge acceleration module.
Yes, at uniform motion around a circle (say, in a magnetic field) the charge has centripetal acceleration and, therefore, radiates electromagnetic waves. Fast electrons in gas-discharge tubes, when they hit the walls, are decelerated with a very large acceleration in absolute value; therefore, near the walls is registered x-rays high energy (so-called bremsstrahlung).
Electromagnetic waves have been transverse- oscillations of the vectors of the electric field strength and magnetic field induction occur in a plane perpendicular to the direction of wave propagation.
Consider, for example, the radiation of a charge that performs harmonic oscillations with a frequency along the axis around the origin. Electromagnetic waves run in all directions from it - in particular, along the axis. On fig. 5 shows the structure of the emitted electromagnetic wave at a large distance from the charge at a fixed time.
Rice. 5. Sinusoidal electromagnetic wave
The wave speed is directed along the axis. The vectors and at each point of the axis perform sinusoidal oscillations along the axes and, respectively, while changing in phase.
The shortest vector-to-vector rotation is always counter-clockwise when viewed from the end of the vector.
At any fixed moment of time, the distribution along the axis of values of the modulus of vectors and has the form of two in-phase sinusoids located perpendicular to each other in the and planes, respectively. Wavelength is the distance between the two nearest points of the axis at which the field values fluctuate in the same phase (in particular, between the two nearest field maxima, as in Fig. 5).
The frequency with which the values of and change at a given point in space is called electromagnetic wave frequency; it coincides with the oscillation frequency of the radiating charge. The length of an electromagnetic wave, its frequency and propagation velocity c are related by the standard relation for all waves:
(2)
Experiments have shown that electromagnetic waves have the same basic properties as other types of wave processes.
1. wave reflection. Electromagnetic waves are reflected from a metal sheet - this was discovered by Hertz. The angle of reflection is equal to the angle of incidence.
2. Wave absorption. Electromagnetic waves are partially absorbed when passing through a dielectric.
3. Refraction of waves. Electromagnetic waves change their direction of propagation when passing from air to a dielectric (and generally at the interface between two different dielectrics).
4. Wave interference. Hertz observed the interference of two waves: the first came to the receiving vibrator directly from the radiating vibrator, the second - after preliminary reflection from the metal sheet.
By changing the position of the receiving vibrator and fixing the positions of the interference maxima, Hertz measured the wavelength . The frequency of natural oscillations in the receiving vibrator was known to Hertz. According to formula (2), Hertz calculated the propagation velocity of electromagnetic waves and obtained approximately m/s. This is exactly the result predicted by the theory constructed by Maxwell!
5. Wave diffraction. Electromagnetic waves go around obstacles whose dimensions are commensurate with the wavelength. For example, radio waves with a wavelength of several tens or hundreds of meters go around houses or mountains that are in their path of propagation.
Radiation Flux Density
Electromagnetic waves carry energy from one part of space to another. Energy transfer is carried out along rays- imaginary lines indicating the direction of wave propagation (we do not give a strict definition of the concept of a ray and hope for your intuitive understanding, which will be quite enough for now).
The most important energy characteristic of electromagnetic waves is the radiation flux density.
Imagine a platform with an area located perpendicular to the rays. Let us assume that during the time the wave transfers energy through this area. Then radiation flux density is defined by the formula:
(3)
In other words, the radiation flux density is the energy transferred through a unit area (perpendicular to the rays) per unit time; or, which is the same, is the radiation power transferred through a single area. The unit for measuring the radiation flux density is W/m2.
The radiation flux density is related by a simple relation to the energy density of the electromagnetic field.
We fix the area perpendicular to the rays, and a small period of time . Energy will pass through the platform:
(4)
This energy will be concentrated in a cylinder with a base area and a height (Fig. 6), where is the speed of the electromagnetic wave.
Rice. 6. To the derivation of formula (6)
The volume of this cylinder is: Therefore, if is the energy density of the electromagnetic field, then for the energy we also get:
(5)
Equating the right parts of formulas (4) and (5) and reducing by , we obtain the relation:
(6)
The radiation flux density characterizes, in particular, the degree of influence of electromagnetic radiation on its receivers; when talking about intensity electromagnetic waves, they mean precisely the density of the radiation flux.
An interesting question is how the intensity of radiation depends on its frequency.
Let an electromagnetic wave be emitted by a charge that performs harmonic oscillations along the axis according to the law. The cyclic frequency of charge oscillations will be at the same time the cyclic frequency of the emitted electromagnetic wave.
For the speed and acceleration of the charge, we have: and . As we see, . The electric field strength and the magnetic field induction in an electromagnetic wave are proportional to the charge acceleration: and . So, and .
The energy density of the electromagnetic field is the sum of the energy density of the electric field and the energy density of the magnetic field: . The energy density of the electric field, as we know, is proportional to the square of the field strength: . Similarly, it can be shown that . Therefore, and , so .
According to formula (6), the radiation flux density is proportional to the energy density: . That's why . We got an important result: the intensity of electromagnetic radiation is proportional to the fourth power of its frequency.
Another important result is that radiation intensity decreases with increasing distance to the source. This is understandable: after all, the source radiates in different directions, and as it moves away from the source, the radiated energy is distributed over an ever larger area.
The quantitative dependence of the radiation flux density on the distance to the source is easy to obtain for the so-called point source of radiation.
Point source of radiation is a source, the size of which can be neglected under the conditions of this situation. In addition, a point source is considered to radiate equally in all directions.
Of course, a point source is an idealization, but in some problems this idealization works great. For example, when studying the radiation of stars, they can be considered as point sources - after all, the distances to stars are so huge that their own sizes can be ignored.
At a distance from the source, the radiated energy is uniformly distributed over the surface of a sphere of radius . The area of a sphere, recall, . If the radiation power of our source is , then energy passes through the surface of the sphere in time. Using formula (3), we then obtain:
In this way, the radiation intensity of a point source is inversely proportional to the distance to it.
Types of electromagnetic radiation
The spectrum of electromagnetic waves is unusually wide: the wavelength can be measured in thousands of kilometers, or it can be less than a picometer. However, this entire spectrum can be divided into several characteristic wavelength ranges; within each range, electromagnetic waves have more or less similar properties and methods of radiation.
We will consider these ranges in descending order of wavelength. The ranges smoothly transition into each other, there is no clear boundary between them. Therefore, the boundary values of wavelengths are sometimes very arbitrary.
1. radio waves(> 1 mm).
The sources of radio waves are charge oscillations in wires, antennas, and oscillatory circuits. Radio waves are also emitted during thunderstorms.
Ultra long waves (> 10 km). They spread well in water, so they are used to communicate with submarines.
Long waves(1 km Medium waves (100m Short waves (10 m) Meter waves (1 m Decimeter waves (10 cm Microwave(1 cm Millimeter waves (1 mm Infrared radiation (780 nm thermal - when it hits our body, we feel heat. Infrared radiation is not perceived by the human eye (some snakes see in the infrared range).
The sun is the most powerful source of infrared radiation. Incandescent lamps emit the largest amount of energy (up to 80%) in just in the infrared region of the spectrum.
Infrared radiation has a wide range of applications: infrared heaters, consoles remote control, night vision devices, drying coatings and much more.
As body temperature rises, the wavelength of infrared radiation decreases, shifting towards visible light. By putting a nail into the flame of a burner, we can observe it with our own eyes: at some point, the nail “is red-hot”, starting to radiate in the visible range.
3. visible light(380 nm spectral colors.
Red: 625 nm - 780 nm;
Orange: 590 nm - 625 nm;
Yellow: 565 nm - 590 nm;
Green: 500 nm - 565 nm;
Cyan: 485 nm - 500 nm;
Blue: 440 nm - 485 nm;
Violet: 380 nm - 440 nm.
The eye has maximum sensitivity to light in the green part of the spectrum. That is why school boards according to GOST should be green: looking at them, the eye experiences less stress.
4. Ultraviolet radiation (10 nm X-ray radiation (5 pm bremsstrahlung), as well as during some transitions of electrons inside atoms from one level to another ( characteristic radiation).
X-ray radiation easily penetrates the soft tissues of the human body, but is absorbed by calcium, which is part of the bones. This enables the well-known x-rays to you.
You must have seen the action at airports X-ray television introscopes- these devices shine through x-rays hand luggage and luggage.
The wavelength of X-ray radiation is comparable with the sizes of atoms and interatomic distances in crystals; therefore, crystals are natural diffraction gratings for x-rays. By observing the diffraction patterns obtained when X-rays pass through various crystals, one can study the arrangement of atoms in crystal lattices and complex molecules.
Yes, with the help of x-ray diffraction analysis the structure of a number of complex organic molecules was determined - for example, DNA and hemoglobin.
In high doses, X-ray radiation is dangerous for humans - it can cause cancer and radiation sickness.
6. Gamma radiation(synchrotron radiation).
In large doses, gamma radiation is very dangerous for humans: it causes radiation sickness and oncological diseases. But in small doses, it can suppress the growth of cancerous tumors and therefore is used in radiotherapy.
The bactericidal effect of gamma radiation is used in agriculture(gamma sterilization of agricultural products before long-term storage), in Food Industry(preservation of products), as well as in medicine (sterilization of materials).
"Theory of radiation" - Radiation of a completely black body. Thus, Respectively and. 1.6. Planck's theory. Spectral emissivity of a black body. X. 1.5. Rayleigh-Jeans formula. 3) Also from the Planck formula, you can get the Stefan-Boltzmann law: Figure 1.2. 1.1. Luminescence and thermal radiation.
"Scale of electromagnetic radiation" - Differences: General properties: What is the source of electromagnetic waves? What is an electromagnetic wave? What's the Difference mechanical waves from electromagnetic? Which of the two types of waves is it? Scale of electromagnetic radiation. Is there a phenomenon of polarization for sound waves in air?
"Types of radiation" - Gamma quanta are high-energy photons. Types of radiation. doses of radiation. The act of decay. First meeting. Today we know about three types of radiation: alpha, beta and gamma. The amount of such energy transferred to the body is called the dose. Beta cure. Alpha radiation. Gamma radiation.
"Population Location and Density" - Average population density by region. Topic: Location and population density. The highest population density is observed in natural areas…., …. Placement and population density: a view from space. Population density map of Austria. Natural. Calculation of world population density using a table. Location and population density of the world.
Tasks: In the 8th grade, we briefly got acquainted with the sources of light. excited atom. Plan. Scale of electromagnetic radiation. Nobel Prize 1901 Infrared radiation. Wavelength 10-8 cm. Purpose. Energy. Energy chemical reaction. Now we must get acquainted with the radiation of light by bodies. Wilhelm Conrad Roentgen.
"Radiation and Spectra" - Chemiluminescence. Photoluminescence. Radiation of a hydrogen atom. In nature, we can observe the spectrum when a rainbow appears in the sky. The striped spectrum consists of individual bands separated by dark gaps. Spectra, Thermal radiation. For example, a daylight lamp. Back to diagram. Heat sources are: The sun, a flame of fire, or an incandescent lamp.
Now let's move on to the consideration of the properties and characteristics of electromagnetic waves. One of the characteristics of electromagnetic waves is the density of electromagnetic radiation.
Consider a surface with an area S through which electromagnetic waves carry energy.
The density of the electromagnetic radiation flux I refers to the ratio of electromagnetic energy Wpassing in time t through a surface of area S perpendicular to the rays, to the product of area S and time t.
The radiation flux density, in SI, is expressed in watts per square meter (W / m 2). Sometimes this quantity is called the intensity of the wave.
After a series of transformations, we get that I = w c.
i.e., the density of the radiation flux is equal to the product of the density of electromagnetic energy and the speed of its propagation.
We have met more than once with the idealization of real sources of acceptance in physics: a material point, an ideal gas, etc. Here we will meet with another one.
A radiation source is considered to be a point source if its dimensions are much smaller than the distance at which its effect is estimated. In addition, it is assumed that such a source sends electromagnetic waves in all directions with the same intensity.
Let us consider the dependence of the radiation flux density on the distance to the source.
The energy that electromagnetic waves carry with them is distributed over a larger and larger surface over time. Therefore, the energy transferred through a unit area per unit time, i.e., the radiation flux density, decreases with distance from the source. It is possible to find out the dependence of the radiation flux density on the distance to the source by placing a point source in the center of a sphere with a radius R. the surface area of the sphere S= 4 n R^2. If we assume that the source in all directions during the time t radiates energy W
The density of the radiation flux from a point source decreases in inverse proportion to the square of the distance to the source.
Let us now consider the frequency dependence of the radiation flux density. As you know, the radiation of electromagnetic waves occurs during the accelerated movement of charged particles. The strength of the electric field and the magnetic induction of an electromagnetic wave are proportional to the acceleration a emitting particles. Harmonic acceleration is proportional to the square of the frequency. Therefore, the electric field strength and magnetic induction are proportional to the square of the frequency
The energy density of the electric field is proportional to the square of the field strength. The energy of the magnetic field is proportional to the square of the magnetic induction. The total energy density of the electromagnetic field is equal to the sum of the energy densities of the electric and magnetic fields. Therefore, the radiation flux density is proportional to: (E^2+B^2). From here we get that I is proportional to w^4.
The radiation flux density is proportional to the fourth power of the frequency.
Tasks in Electrodynamics (ELECTROMAGNETIC WAVES), on the topic
Electromagnetic waves and the speed of their propagation. The energy of an electromagnetic wave. Radiation Flux Density. Radar
From the manual: GDZ to the problem book Rymkevich for grades 10-11 in physics, 10th edition, 2006
Is it possible to choose such a reference frame in which the induction of the magnetic field of the electron beam would be equal to zero
SOLUTION
The frame of reference (see the condition of the previous problem) moves at a speed greater than the speed of the electrons in the beam. What can be said about the direction of the field induction lines
SOLUTION
Is it possible to choose such a reference frame in which the magnetic induction of the field of a direct conductor with current would be equal to zero? What can be said about the direction of the lines of induction if the reference frame moves at a speed greater than the speed of the ordered movement of electrons in the conductor
SOLUTION
Why does interference appear when receiving radio transmissions on medium and long waves with the approach of a thunderstorm
SOLUTION
What is the oscillation period in an open oscillatory circuit emitting radio waves with a wavelength of 300 m
SOLUTION
The radio station is transmitting at a frequency of 75 MHz (VHF). Find the wavelength
SOLUTION
In a radio receiver, one of the shortwave ranges can receive transmissions whose wavelength is 24 26 m. Find the frequency range
SOLUTION
Manual setting radio receiver, we change the working area of the plates of an air capacitor of variable capacitance in the receiving oscillatory circuit. How does the working area of the plates change when switching to the reception of a station transmitting at longer wavelengths
SOLUTION
The coil of the receiving circuit of the radio receiver has an inductance of 1 μH. What is the capacitance of the capacitor if a station operating at a wavelength of 1000 m is being received
SOLUTION
The radio receiver is tuned to a radio station operating at a wavelength of 25 m.
SOLUTION
When the current strength in the inductor changes by ΔI \u003d 1 A for the time Δt \u003d 0.6 s, an EMF equal to £ \u003d 0.2 mV is induced in it. What is the length of the radio wave emitted by the generator, the oscillatory circuit of which consists of this coil and a capacitor with a capacitance C \u003d 14.1 nF
SOLUTION
In what range of wavelengths does the receiver operate if the capacitance of the capacitor in its oscillatory circuit can be smoothly changed from 200 to 1800 pF, and the inductance of the coil is constant and equal to 60 μH
SOLUTION
The current strength in an open oscillatory circuit varies depending on time according to the law: i = 0.1 cos 6 105 t. Find the length of the emitted wave
SOLUTION
Determine the length of the electromagnetic wave in vacuum, to which the oscillatory circuit is tuned, if the maximum charge of the capacitor is 20 nC, and the maximum current in the circuit is 1 A
SOLUTION
How many oscillations occur in an electromagnetic wave with a wavelength of 300 m in a time equal to the period sound vibrations with a frequency of 2000 Hz
SOLUTION
The shortest distance from Earth to Saturn is 1.2 km. After what minimum period of time can response information be received from a spacecraft located in the region of Saturn to a radio signal sent from Earth
SOLUTION
The repeater of the television program Orbita is installed on the communication satellite Raduga, which moves in a circular orbit at an altitude of 36,000 km above the Earth's surface, occupying a constant position relative to the Earth. How long does the signal propagate from the transmitting station to the TVs of the Orbita system
SOLUTION
At what distance from the radar antenna is the object if the radio signal reflected from it returned back after 200 µs
SOLUTION
At a distance of 300 m from the Ostankino television tower, the radiation flux density is maximum and equal to 40 mW/m2. What is the radiation flux density at a reliable reception distance of 120 km
SOLUTION
The energy density of an electromagnetic wave is 4 10-11 J/m3. Find the radiation flux density
SOLUTION
The radiation flux density is 6 mW/m2. Find the energy density of an electromagnetic wave
SOLUTION
The maximum strength of the electric field of an electromagnetic wave according to sanitary standards should not exceed 5 V/m. Find the allowable flux density of electromagnetic radiation
SOLUTION
The pulse power of the radar station is 100 kW. Find the maximum electric field strength of the wave at the point where the cross-sectional area of the radiation cone is 2.3 km2
SOLUTION
What can be the maximum number of pulses sent by the radar in 1 s when reconnaissance of a target located at a distance of 30 km from it
SOLUTION
The radar operates at a wavelength of 15 cm and gives 4000 pulses per 1 s. The duration of each pulse is 2 μs. How many oscillations are contained in each pulse and what is the depth of exploration of the locator
SOLUTION
The horizontal sweep time of the cathode ray tube of the radar is 2 ms. Find the greatest depth of exploration
SOLUTION
The radar operates in a pulsed mode. The pulse repetition frequency is 1700 Hz, and the pulse duration is 0.8 μs. Find the largest and smallest target detection range of a given radar