physics lab instruments
physics lab instruments
with definition ,components ,working principal and application.
1. Vernier Caliper
Definition:
A vernier scale (Vernier Caliper) is a visual aid to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation; thereby increasing resolution and reducing measurement uncertainty by using Vernier acuity to reduce human estimation error.
Components:
Internal jaws,External jaws, Main arm,Sliding arm, Depth measuring probe,Locking Screw.
Working principal:
The vernier scale works on the principle of using alignment of line segments displaced by a small amount to make fine measurements. Human eye can easily detect this alignment of lines which is the main fact that drives a vernier. A vernier scale has a main scale and a vernier scale.
Applications:
Uses of Vernier Calipers. We know the core uses of Vernier Calipers is for measuring the distance between two opposite side of a surface. We can measure the internal and external dimension and even height of an object with accuracy. It can measure upto one hundredth of a millimeter.
2. micrometer screw gauge
Definition:crew gauge or micrometer screw gauge is a measuring instrument used for precision measurement. A measuring device used extensively in the mechanical engineering field, micrometer screw gauge is used for measuring extremely small dimensions. A screw gauge can even measure dimensions smaller than those measured by a Vernier Caliper. Belonging to the family of calipers, micrometer screw gauges also consists of two different scales.
Components:
Thus the main parts of a micrometer screw gauge are:
- Frame.
- Anvil.
- Spindle.
- Sleeve.
- Thimble.
- Ratchet.
- Screw.
- Lock.
Working principal:
Working Principle Micrometer Screw gauge works on the simple principle of converting small distances into larger ones by measuring the rotation of the screw. This “screw” principle facilitates reading of smaller distances on a scale after amplifying them.To simply it further, let's take a normal screw with threads.
Applications:
Screw gauge is used to find the diameter of a steel rod that is used in the construction of a building. It is used in the industry to manufacture components of a machine with required measurements. As this instrument is used to measure the gauge of a metal sheet or a wire, it is named as screw gauge.
3. spherometer
Definition:
A spherometer is an instrument for the precise measurement of the radius of curvature of a sphere or a curved surface. Originally, these instruments were primarily used by opticians to measure the curvature of the surface of a lens.
Components:
- A base circle of three outer legs, a ring, or the equivalent, having a known radius of the base circle. ...
- A central leg, which can be raised or lowered.
- A reading device for measuring the distance the central leg is moved.
Working principal:
A spherometer works on the principle of the micrometer screw. It is used to measure either very small thickness of flat materials like glass or the radius of curvature of a spherical surface thus getting its name.
Applications:
Spherometers are small precision instruments for measuring the radius of curvature of spherical surfaces. The term may also be spelled as a "spheremeter" or "sphereometer". The most common application of a spherometer is the measurement of an unknown lens shape, in order to study its optical characteristics.
4. Ammeter
Definition:An ammeter (from Ampere Meter) is a measuring instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters.
components:
The iron element consists of a moving vane attached to a pointer, and a fixed vane, surrounded by a coil.
Working principal:
The main principle of ammeter is that it must have a very low resistance and also inductive reactance. ... For an ideal ammeter, it must have zero impedance so that it has zero voltage drop across it so the power loss in the instrument is zero. But the ideal is not achievable practically.
Applications:
An ammeter is an instrument used for measuring electric current in units of amperes. An ammeter must be connected in series with the path of the current being measured. Setting the ammeter up in parallel will create a short circuit and will not measure the current correctly.
5. voltmeter
Definition:
A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an analog to digital converter.
Components:
A voltmeter is basically a galvanometer with a high series resistance also known as shunt resistors. The voltmeter is connected in parallel to the circuit to measure the voltage.
Working principal:
Voltmeter works on the principle of Ohm's law, which states that the voltage across a resistance is directly proportional to the current passing through it. ... In orders to convert this ammeter into a galvanometer, we attach a large resistance in series with the coil of the galvanometer.
Applications:
A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an analog to digital converter.
6. Galvanometer
Definition:
A galvanometer is an electromechanical instrument used for detecting and indicating an electric current. A galvanometer works as an actuator, by producing a rotary deflection (of a "pointer"), in response to electric current flowing through a coil in a constant magnetic field.
Components:
Working principal:
The moving coil galvanometer working principle is based upon the fact that when electric current flows in a coil placed in a magnetic field, a deflecting torque acts upon the coil whose magnitude depends upon the strength of the current.
Applications:
Galvanometer is an electromechanical device, an instrument, which is used to detect and measure electric current. They were also used as the analog measuring instruments (known as ammeters) to measure the direct flow of electric charge (current) that flows through an electric circuit.
7. Resistance box
Definition:
The box which contains the resistors of different values for estimating and comparing the resistance is known as the resistance box. The accuracy of the resistance box is very high. The main application of the resistance box is to control the specific value of current to flow through the circuit.
Working principal:
In resistance box, the resistor is fixed inside the box. They are arranged in such a manner that the value of resistance varies at every step. The box consists the rotary selector switch. The variable resistances are obtained by rotating the selector switches.
Applications:
The main application of the resistance box is to control the specific value of current to flow through the circuit. The main advantage of the resistance box is that the variable resistances are available at one point.
8. rheostat
Definition:
A rheostat is a variable resistor which is used to control current. They are able to vary the resistance in a circuit without interruption. The construction is very similar to the construction of a potentiometers.
Components:
a rheostat has three terminals, two fixed and one moving. Also, this moving terminal slides over a resistive path. This resistive path can be of any type of resistive material such as carbon composition resistor, wire-wound resistor, conductive plastic resistor and ceramic resistor.
Working principal:
The basic principle that rheostats use is Ohm's law, which states that current is inversely proportional to resistance for a given voltage. This means the current decreases as the resistance increases or it increases as the resistance decreases.
Applications:
Rheostat is generally used in the applications where high voltage or current is required. Rheostats are used in dim lights to change the intensity of light. If we increase the resistance of the rheostat, the flow of electric current through the light bulb decreases. As a result, the light brightness decreases.
9. Prism
Definition:
a glass or other transparent object in the form of a prism, especially one that is triangular with refracting surfaces at an acute angle with each other and that separates white light into a spectrum of colours.
Working principal:
A prism is a clear, triangular device made up of plastic or glass (or any transparent material). When white light goes through a prism, the light bends due to the phenomenon called refraction. Refraction is the process of bending light as light goes from one medium (like air) to another medium (like water or glass).
Applications:
Mostly used in telescopes, periscopes and microscopes, scientists also use prisms in experiments that help them study the reaction of the human eye to light. Prisms constitute any three-dimensional shape with two faces of the same size and shape and parallelogram sides.
10. multimeter
Definition:
A multimeter or a multitester, also known as a VOM (volt-ohm-milliammeter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter can measure voltage, current, and resistance. Analog multimeters use a microammeter with a moving pointer to display readings.
Components:
Following components inside a multimeter are:
- A/D converter.
- Digital Display.
- Digital controller.
- Battery.
- Input signal conditional and converter.
- Differential amplifier.
- Switch.
Working principal:
Digital voltmeter is the basic instrument used for measurement of voltage through the use of Analog to Digital converter. The basic principle behind digital multimeters is the Analog to digital converter because without this we are not able to convert the analog output into digital form.
Applications:
Multimeter is mainly used to measure the three basic electrical characteristics of voltage, current and resistance. It can also be used to test continuity between two points in a electrical circuit. ... Multimeters can be used for testing batteries, household wiring, electric motors and power supplies.
11.barometer
Definition:
A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis to help find surface troughs, pressure systems and frontal boundaries.
Components:
Working principal:
A barometer is essentially a balance. The weight of the atmosphere is balanced by the weight of a much shorter mercury column. You can't use an ordinary pan balance to weight the atmosphere (because air is pushing down on both sides).Air pressure at any level in the atmosphere depends on the weight of the air overhead. A mercury barometer is basically just a scale that measures the weight of the atmosphere above.
Applications:
Barometer, device used to measure atmospheric pressure.
12.lens
Definition:
A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (elements), usually arranged along a common axis.
Working principal:
Optical principles for lenses. A lens produces its focusing effect because light travels more slowly in the lens than in the surrounding air, so that refraction, an abrupt bending, of a light beam occurs both where the beam enters the lens and where it emerges from the lens into the air.
Applications:
Convex lenses are used to correct farsighted vision problems. Similarly, concave lenses are used to correct nearsightedness. Compound microscopes and telescopes use both convex and concave lenses.
13. hydrometer
Definition:
A hydrometer is an instrument used to measure the specific gravity or relative density of liquids, i.e. the ratio of the density of the liquid to the density of water. Hydrometers are usually made of glass and consists of a cylindrical stem and a bulb weighted with a heavy material to make it float upright.
Components:
A hydrometer usually consists of a sealed hollow glass tube with a wider bottom portion for buoyancy, a ballast such as lead or mercury for stability, and a narrow stem with graduations for measuring.
Working principal:
Hydrometers function based on Archimedes' principle or the principle of flotation, which states a solid suspended in a fluid will be buoyed up by a force equal to that of the weight of the fluid that is displaced. So, a hydrometer sinks further into a liquid of low density than into one of high density.
Applications:
A hydrometer is an instrument that measures the specific gravity of liquids. A hydrometer accomplishes this by measuring the amount of water it displaces. Hydrometers are commonly used by winemakers to determine the sugar content of wine, and they're also used in soil analysis.
14. laser
Definition:
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation".
Components:
Some of the major components of a laser cutter are as follows:
- Laser Cutter Frame.
- Laser generator.
- CNC system.
- Reflector Path.
- Power Supply.
- Control platform.
- Cutting head.
- Water chiller.
Working principal:
Applications:
Lasers are powerful beams of electromagnetic radiation. ... Applications in Medical applications, welding and Cutting, surveying, garment industry, laser nuclear fusion, communication, laser printing, CDs and optical discs, spectroscopy, heat treatment, barcode scanners, laser cooling
15. optical bench
Definition:
The optical bench is commonly used in physics labs today, and consists of a long, rigid member with a linear scale applied to it. Holders for light sources, lenses and screens are placed on the apparatus so that image formation can be observed.
Working principal:
When light rays strike the surface of a lens, they are refracted as they pass from air through the material of the lens. When they emerge on the other side and pass from the lens to the air, they are refracted again. Convex lenses are curved so that the center of the lens is thicker than the sides.
Applications:
The main use of the optical benches is to observe the image formation. It is used to study the thermal radiation. They are also used to study the rate of emission from different surfaces that are held at the same temperature.
16. Thermometer
Definition:
A thermometer is used to measure how hot or cold something is. There is a number scale showing temperature going from cold at the bottom to hot higher up. There are different types of thermometer and some are electrical.
Components:
The main parts of a mercury thermometer are the capillary, the bulb, the scale, and the expansion chamber.Made up of thermo (heat) and meter (measuring device), the meaning of the word thermometer is pretty straightforward.
Working principal:
The measurement of temperature is performed by the thermometer by using mercury, which - when heated - expands, and contracts in response to a fall in temperature. This causes the length of the liquid column to be longer or shorter depending on the temperature.
Applications:
Thermometers are used to see if you have a fever or tell you how cold it is outside. Made up of thermo (heat) and meter (measuring device), the meaning of the word thermometer is pretty straightforward.Thermometers measure temperatures in degrees, according to either the Celsius or Fahrenheit system.
17.Spectrometer
Definition:
A spectrometer is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the spectral components are somehow mixed.
Components:
The Spectrometer. ...
What can the Spectrometer Measure? ...
The Rhea - The Key Components of a Spectrometer. ...
The Filters. ...
The Slit. ...
The Concave Mirror. ...
The Diffraction Grating. ...
The Detector - A Charge Coupled Device (CCD)
What can the Spectrometer Measure? ...
The Rhea - The Key Components of a Spectrometer. ...
The Filters. ...
The Slit. ...
The Concave Mirror. ...
The Diffraction Grating. ...
The Detector - A Charge Coupled Device (CCD)
Working principal:
The basic principle is that each compound absorbs or transmits light over a certain range of wavelength.The basic function of a spectrometer is to take in light, break it into its spectral components, digitize the signal as a function of wavelength, and read it out and display it through a computer. ... In most spectrometers, the divergent light is then collimated by a concave mirror and directed onto a grating.
Applications:
A spectrometer is a device for measuring wavelengths of light over a wide range of the electromagnetic spectrum. It is widely used for spectroscopic analysis of sample materials. The incident light from the light source can be transmitted, absorbed or reflected through the sample.
18. Tapping key
Definition:
Definition of tapping key. : a light flexible metallic strip provided with contacts so that when it is momentarily pressed an electric circuit is made or broken and when it is released the opposite effect is automatically produced.
Components:
Mounted on bakelite base, all metal parts nickel plated brass.two power ports and switch.
Working principal:
it's working principle is simple as a normal switch
Applications:
Contact Tap Key (Tapping Key) For providing momentary contact in electrical circuits which are normally open. Can also be used in morse code applications.
19. Viscometer
Definition:
A viscometer (also called viscosimeter) is an instrument used to measure the viscosity of a fluid. For liquids with viscosities which vary with flow conditions, an instrument called a rheometer is used.
Components:
Equipment Design. The rotational viscometer consists of two basic parts separated by the fluid being tested. The two parts may be: concentric cylinders (cup and bob), parallel plates, a low angle cone and plate, or a spindle inside of a cylinder. Common spindle shapes, disk, T-bar, cylinder, and vane, are shown below.
Working principal:
viscometers work by getting the measurements of the torque on a vertical stand that moves the spindle in a rotational direction. The rotation of the spindle is usually proportional to how viscous the sample is.
Applications:
viscometers are used to measure viscosity.
20. Battery
Definition:
A battery is a device consisting of one or more electrochemical cells with external connections for powering electrical devices such as flashlights, mobile phones, and electric cars. When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode.
Components:
There are three main components of a battery: two terminals made of different chemicals (typically metals), the anode and the cathode; and the electrolyte, which separates these terminals. The electrolyte is a chemical medium that allows the flow of electrical charge between the cathode and anode.
Working principal:
A battery works on the oxidation and reduction reaction of an electrolyte with metals. When two dissimilar metallic substances, called electrode, are placed in a diluted electrolyte, oxidation and reduction reaction take place in the electrodes respectively depending upon the electron affinity of the metal of the electrodes.the general principle of electrons going around the outer circuit, and ions reacting with the electrolyte (moving into it or out of it), applies to all batteries.
Applications:
The major application of lead acid battery is in starting, lightning, and ignition systems(SLI) of automobiles. Its other form, wet cell battery is used as backup power supply for high end servers, personal computers, telephone exchanges, and in off grid homes with inverters.
21.Capacitor
Definition:
A capacitor is a device that stores electrical energy in an electric field. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance.
Components:
A capacitor is an electronic component that takes advantage of the ability of electric fields to reach out across an insulator. It consists of two flat plates made from a conducting material such as silver or aluminum, separated by a thin insulating material such as Mylar or ceramic.
Working principal:
Principle of a capacitor : A capacitor works on the principle that the capacitance of a conductor increase appreciably when an earthed conductor is brought near it. Thus a capacitor has two plates separated by a distance having equal and opposite charges.
Applications:
The most common use for capacitors is energy storage. Additional uses include power conditioning, signal coupling or decoupling, electronic noise filtering, and remote sensing. Because of its varied applications, capacitors are used in a wide range of industries and have become a vital part of everyday life.
22. resistor
Definition:
Resistor is an electrical component that reduces the electric current. The resistor's ability to reduce the current is called resistance and is measured in units of ohms (symbol: Ω). If we make an analogy to water flow through pipes, the resistor is a thin pipe that reduces the water flow.
Components:
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
Working principal:
The main purpose of a resistor is to maintain specified values of voltage and current in an electronic circuit. A Resistor works on the principle of Ohm's law and the law states that the voltage across the terminals of a resistor is directly proportional to the current flowing through it. The unit of resistance is Ohm.
Applications:
resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
23. inductor
Definition:
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil around a core.
Components:
An inductor typically consists of an insulated wire wound into a coil around a core.
Working principal:
An inductor is a passive electronic component which is capable of storing electrical energy in the form of magnetic energy. Basically, it uses a conductor that is wound into a coil, and when electricity flows into the coil from the left to the right, this will generate a magnetic field in the clockwise direction.
Applications:
Two applications of inductors are their use as filters and sensors. Inductors are commonly used with capacitors in an electrical circuit to create a filter that only allows a certain frequency to pass through the circuit, making them an essential component of electronics.
24. photoresistor
Definition:
A photoresistor is a type of resistor whose resistance decreases when the intensity of light increases. In other words, the flow of electric current through the photoresistor increases when the intensity of light increases.
Components:
Modern light dependent resistors are made of lead sulfide, lead selenide, indium antimonide, and most commonly cadmium sulfide and cadmium selenide. The popular cadmium sulfide types are often indicated as CdS photoresistors.
Working principal:
When light falls on the photosensitive material (or on the Photoresistor), the valence electrons absorb the light energy and break free from the nucleus to become free electrons. These electrons lead to flow of current when an external force like an electric field is applied.
Applications:
Some of the Photoresistors are used in some of the consumer items like light meters in camera, light sensors like in robotic projects, clock radios etc. They are also used to control the reduction in gain of dynamic compressors.
25. diode
Definition:
A diode is defined as a two-terminal electronic component that only conducts current in one direction (so long as it is operated within a specified voltage level). An ideal diode will have zero resistance in one direction, and infinite resistance in the reverse direction.
Components:
A diode is an electronics component made from a combination of a P-type and N-type semiconductor material, known as a p-n junction, with leads attached to the two ends. ... The lead attached to the n-type semiconductor is called the cathode. Thus, the cathode is the negative side of the diode.
Working principal:
Its working principle is when the diode is reverse biased, small leakage currents pass through the diode, when the reverse voltage is further increased the leakage current also increases which are fast enough to break few covalent bonds within the junction these new charge carriers further breaks down the remaining ...
Applications:
Here are a few of the typical applications of diodes include:
- Rectifying a voltage, such as turning the AC into DC voltages.
- Isolating signals from a supply.
- Voltage Reference.
- Controlling the size of a signal.
- Mixing signals.
- Detection signals.
- Lighting systems.
- LASER diodes.
26.Transistor
Definition:
A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit.
Components:
Transistors are composed of three parts ' a base, a collector, and an emitter. The base is the gate controller device for the larger electrical supply. The collector is the larger electrical supply, and the emitter is the outlet for that supply.
Working principal:
The fundamental principle behind all transistors is simple: Current flow between two terminals is prevented by an energy barrier that has been set up between them. To operate the transistor, a third terminal is provided that allows you to lower the energy barrier.
Applications:
Transistors are a three terminal semiconductor device used to regulate current, or to amplify an input signal into a greater output signal. Transistors are also used to switch electronic signals. ... Most types of transistors are packaged individually but can also be included in an integrated circuit.
27. phototransistor
Definition:
The phototransistor is a semiconductor device that is able to sense light levels and alter the current flowing between emitter and collector according to the level of light it receives.
Components:
Phototransistors are semiconductor devices based around the basic bipolar transistor. Along with other electronic components and semiconductor devices they are available from virtually all component distributors and often their cost is very low.
Working principal:
Applications:
- The phototransistor is widely used in electronics devices likes smoke detectors, infrared receiver, CD players, lasers etc. for sensing light.
- They also find applications in Opto-isolators, Position sensing, Security systems, Coin counters, etc.
28.light emitting diode
Definition:
A light-emitting diode (LED) is a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons.
Components:
Unlike normal signal diodes which are made for detection or power rectification, and which are made from either Germanium or Silicon semiconductor materials, Light Emitting Diodes are made from exotic semiconductor compounds such as Gallium Arsenide (GaAs), Gallium Phosphide (GaP), Gallium Arsenide Phosphide (GaAsP), ...
Working principal:
Working Principle: A light-emitting diode is a two-lead semiconductor light source. It is a p–n junction diode that emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons.
Applications:
A light-emitting diode (LED) is a semiconductor light source that emits light when current flows through it. ... Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red.
29. solar cell
Definition:
A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
Components:
It essentially consists of a silicon PN junction diode with a glass window on top surface layer of P material is made extremely thin so, that incident light photon's may easily reach the PN junction. ... In this way free electrons and holes are generated on both sides of the junction.
Working principal:
Working Principle of Solar Cell. When light reaches the p-n junction, the light photons can easily enter in the junction, through very thin p-type layer. The light energy, in the form of photons, supplies sufficient energy to the junction to create a number of electron-hole pairs.
Applications:
Uses of solar cells. Solar cells are very useful in powering space vehicles such as satellites and telescopes (e.g. Hubble). They provide a very economical and reliable way of powering objects which would otherwise need expensive and cumbersome fuel sources.
30. motor
Definition:
A motor is a device that changes a form of energy into mechanical energy to produce motion. Electric motors convert electrical energy into mechanical energy. The generator may be driven by a motor connected to the electricity supply.
Components:
Electric motor designs can vary quite a lot, though in general they have three main parts: a rotor, a stator and a commutator. These three parts use the attractive and repulsive forces of electromagnetism, causing the motor to spin continually as long as it receives a steady flow of electric current.
Working principal:
An electric motor is an electrical machine which converts electrical energy into mechanical energy. The basic working principle of a DC motor is: "whenever a current carrying conductor is placed in a magnetic field, it experiences a mechanical force".
Applications:
The applications of electrical motor include the following. The applications of electrical motor mainly include blowers, fans, machine tools, pumps, turbines, power tools, alternators, compressors, rolling mills, ships, movers, paper mills.
31. Bulb
Definition:
Light bulbs convert electricity into light and heat. Except for heat lamps, the heat is considered waste. A light bulb that produces more light and less heat is more efficient.
Components:
Parts of a light bulb: the glass globe, the metal filament, wires and glass stem, gases and metal base.
Working principal:
An incandescent bulb works on the principle of incandescence, a general term meaning light produced by heat. In an incandescent type of bulb, an electric current is passed through a thin metal filament, heating the filament until it glows and produces light.
Applications:
A light bulb produces light from electricity. In addition to lighting a dark space, they can be used to show an electronic device is on, to direct traffic, for heat, and for many other purposes. Billions are in use, some even in outer space. Early people used candles and oil lamps for light.
32. potentiometer
Definition:
A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat.
Components:
Potentiometers consist of a resistive element, a sliding contact (wiper) that moves along the element, making good electrical contact with one part of it, electrical terminals at each end of the element, a mechanism that moves the wiper from one end to the other, and a housing containing the element and wiper.
Working principal:
The potentiometer works on the principle that when a constant current flows through a wire of uniform cross sectional area, potential difference between its two points is directly proportional to the length of the wire between the two points.
Applications:
The Potentiometer is an electric instrument that used to measure the EMF (electro motive force) of a given cell, the internal resistance of a cell. And also it is used to compare EMFs of different cells. It can also use as a variable resistor in most of the applications.
33. Integrated circuit
Definition:
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material that is normally silicon. The integration of large numbers of tiny MOS transistors into a small chip results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components.
Components:
An integrated circuit (also called an IC or just a chip) is an entire electronic circuit consisting of multiple individual components such as transistors, diodes, resistors, capacitors, and the conductive pathways that connect all the components, all made from a single piece of silicon crystal.
Working principal:
Each electronic component has a specific function, and when they are combined with each other, they can perform multiple tasks and calculations. We will discuss the functions of these components briefly.
Applications:
Linear IC's also known as analog Integrated circuits are used in :
- Power amplifiers.
- Small-signal amplifiers.
- Operational amplifiers.
- Microwave amplifiers.
- RF and IF amplifiers.
- Voltage comparators.
- Multipliers.
- Radio receivers.
34. zener diode
Definition:
A Zener diode is a type of diode that allows current to flow in the conventional manner - from its anode to its cathode i.e. when the anode is positive with respect to the cathode
Components :
A Zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.
Working principal:
In electronics, the Zener effect (employed most notably in the appropriately named Zener diode) is a type of electrical breakdown, discovered by Clarence Melvin Zener. It occurs in a reverse biased p-n diode when the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor, leading to numerous free minority carriers which suddenly increase the reverse current.
Applications:
Zener diodes are used for voltage regulation, as reference elements, surge suppressors, and in switching applications and clipper circuits. The load voltage equals breakdown voltage VZ of the diode. The series resistor limits the current through the diode and drops the excess voltage when the diode is conducting.
35. wires
Definition:
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads or electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate.
Components :
Some high-end modern speaker wire consists of multiple electrical conductors individually insulated by plastic, similar to Litz wire. Resistance wire is wire with higher than normal resistivity, often used for heating elements or for making wire-wound resistors. Nichrome wire is the most common type.
Applications:
Wires are used to bear mechanical loads or electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate.