Lambert's law

Lambert's law or also known as beer lambert's law establishes the empirical relationship connecting the absorption of light and the properties of a material as light travels.

This law was discovered in several different and independent ways, the first to discover it was the Frenchman Pierre Bouguer in 1729.

The beer-lambert law is composed of Beer's law and Lambert's law. Both laws are based on the behavior of radiation absorbed by a sample. The difference between these two laws is that Lambert's law predicts the effect that the thickness of the medium creates, while Beer's law implies the effect of concentration, both on the fraction of radiation which absorbs.

Lambert's law says that the loss of the intensity at the moment it is in the medium is directly proportional to the intensity and the path length. In other words, if the intensity increases, the length increases and if the intensity decreases the length decreases with it.

The Beer-Lambert law as its main utility is to know the determination of the concentrations of the solutions. Against it, it states that the total amount of light emanating from the sample can decrease due to the following three phenomena:

- Concentration is the number of materials absorbed at the moment of its trajectory.

- Optical path distance à the distance the light has to pass through the element.

- Absorbance à the probability of a photon being absorbed by the sample.

This law establishes the connection between the absorption in the radiation and the density of the sample.

What is the formula of Beer Lambert's law?

The parameters taken into account in this law in addition to the material properties are:

- A: absorbance of the solution at one wavelength

- ɛ: molar extinction coefficient (M-1 - cm-1 )

- b: cuvette pitch length (cm)

- C: concentration of the solution

What are transmittance and absorbance?

In this

law, we find two concepts: Absorbance and transmittance

- Absorbance is the amount of radiation absorbed by a material.

- Transmittance is the proportion of light that passes through a material in a given time.

Watt's law

Watt's law was invented by James Watt, an engineer born in Scotland in August 1819. His law is directly related to the development of the steam engine in 1769 and was patented and used in the first industrial revolution.

Watt is an English word meaning "Watt". On the other hand, it is most commonly used to measure the power of systems. Power is the energy consumed or produced in a limited period.

This law states that: "electrical power is directly proportional to the voltage of a circuit and the current flowing through it. "

Watt's law formulas

To obtain the formula for this law, we can obtain it from the pyramid, like that of OHM's law.

P = V·I

V =Voltage (Volts)

I = Current (amperes)

P = Power (watts)

Watt's law is the electrical power of a component. This power is equivalent to 1J. Watt is also a unit that measures the energy absorbed by an element in a given time.

After the discovery of Watt's law, it was merged with OHM's law. If what is not known about the law invented by James Watt is the voltage, this value can be replaced by the same value of ohm's law. Below, we can see it.

To obtain Watt's law without the voltage value we must follow the following formulae:

P = V · I

P = (I · R) · I

P = I² · R

If the power is positive, it means that the element we are calculating is consuming energy, while if the power is negative, it means that it is creating energy.

Applications of the law in everyday life

In our everyday life, we use Watt's law to know the voltage and power of a light bulb or, to a greater extent, the wiring of a building.

The applications of this law are very diverse, but the most common are:

• Knowing the amount of energy that can be produced by an electrical generator.

• Measuring the electrical power of a building.

Servomechanisms

The initial servomechanism was developed in the course of the 19th century along with temperature and speed controllers focused on water turbines, designed by Woodward in 1870. It was invented by SS Great Eastern who designed the patent. However, the pioneer was McFarlane.

The servomechanism, also known as servo drive, is an instrument that gives us the possibility to transmit a physical magnitude, being able to maintain a ratio between the command and the result.

servomechanisms have several advantages, such as being an instrument that is always constant and maintains the same rhythm. In addition, they can operate at high speeds. On the other hand, the current can be increased while the motor is being driven.

There are several types of servo drives depending on the type of motor: mechanical, hydraulic, pneumatic, electric, and electronic.

All servomechanisms have some characteristics in common, which we can see below.

Artificial → man-made

- Sensory → can be perceived by the stimuli around us.

- Controlled → controls both speed and position

- Actuator → can produce movements by itself

Types of servo motors:

- Positional rotation servo: this type of servo is the most commonly used. The positional rotation servo has limits that take care of the rotation sensor so that it rotates beyond its set physical limits.

- Continuous rotation servo: This servo is like the positional rotation servo, but unlike the positional rotation servo, it does not have a direction stop when rotating.

- Linear servo: The linear servo consists of additional gears in addition to the positional rotation servo.

Where can we find servomechanisms?

Servo motors can be found in various industries, but the most important ones are:

Robotics = focuses on automatic control. More specifically in robotics, we can find them in any robot arm that is needed in an assembly line. The operation is due to mechanical and electrical systems that produce the movements necessary for the machine to function. Any servomechanism is composed of sensors (either speed or positioning sensors), a feedback mechanism, a gear, and a controller.

• Automotive sector = deals with remote control.

Polarization

Polarization is the property that all transverse waves possess that produces a vibration of these with more than one orientation. We can find the direct and the reverse.

Direct polarization occurs when the positive connection (+) is connected to the anode and the negative connection (-) to the cathode. On the other hand, the terminal (+) must be superior to the terminal (-). The external voltage of this direct property is due to the fusion of P and N. More specifically to the negative connection to the type N semiconductor and the positive connection to the semiconductor P. This has a reduced barrier potential, a higher direct current, and a lower resistance than the reverse.

Reverse polarization has the negative terminal in zone P, while it has the positive terminal in zone N. Unlike reverse polarization, it has a strong barrier potential, a lower direct current, and higher resistance.

Methods to measure it

The methods to measure the polarization of light are

• The one of reflection: which occurs at the moment in which natural light penetrates the surface that is in the separation between two media.

• You dare the dispersion: it happens when the waves radiate and disperse at the moment when the light passes through the material.

• The refractive one: happens when the ray of light passes through two means.

• Transmission: employs polaroid filters, which have the function of blocking magnetic and electrical waves.

Types of polarization

We can find different types of polarization depending on the mismatch they find

• Elliptical: it has waves that are displaced by an ellipse-shaped trajectory.

• Linear: the frequencies move in the same plane temporarily. Within this polarization we can find:

Horizontal: Its wave electric field is horizontal to the Earth’s surface.

Vertical: has an electric wave field perpendicular to the surface.

• Circular: their frequencies move by rotating on their axis. Within this classification,we can find:

Dextrogira: its rotating movement is towards the right.

Levógira: its rotating movement is towards the left.

Polarization can be applied in several applications. However, the most frequent are: to differentiate transverse and longitudinal waves and for infrared spectroscopy.