(a)LED: Led is Light emitting diode. It is a PN Junction Diode, which emits light when gets activated. When a suitable energy is applied , electron combines with the electron holes within the device releasing energy in the form of photons.LED lamps have a lifespan and electrical efficiency which are several times longer than incandescent lamps, and significantly more efficient than most fluorescent lamps.
(b)Insulated Gate Bipolar transistor: It is a transistor device and forms the basic component of all electronic devices. It used to amplify or switch electronic signals and electric power. IGBTs is also used to generate the ( mercury) discharge, which lights up the bulb. It can also fit in a small volume.
(c)Properties of tungsten: Tungsten has a very high melting point , it has low vapor pressure and greatest tensile strength out of all the metals. Because of these properties tungsten is used as filament in incandescent bulb.,
Light-Emitting Diodes (LEDs)
A light-emitting diode (LED) is a semiconductor light source. LEDs are used in many applications, including indicator lights, advertising signs, and general lighting.
LEDs work by passing an electric current through a semiconductor material. This causes the material to emit light. The color of the light depends on the type of semiconductor material used.
LEDs are very efficient at converting electricity into light. They are also very durable and have a long lifespan. LEDs are replacing traditional light sources, such as incandescent bulbs and fluorescent tubes, in many applications.
Insulated Gate Bipolar Transistors (IGBTs)
An insulated gate bipolar transistor (IGBT) is a type of transistor that combines the features of a bipolar junction transistor (BJT) and a field-effect transistor (FET). IGBTs are used in a variety of applications, including power electronics, motor control, and power conversion.
IGBTs have several advantages over other types of transistors. They are more efficient, have a higher switching speed, and can handle higher voltages. IGBTs are also relatively easy to manufacture.
Properties of Tungsten
Tungsten is a chemical element with the symbol W and atomic number 74. It is a silvery-white Metal that is hard and brittle. Tungsten has the highest melting point of any metal at 3422 °C. It is also one of the densest metals, with a density of 19.32 g/cm3.
Tungsten is used in a variety of applications, including light bulbs, filaments, X-ray tubes, electrical contacts, spark plugs, welding rods, and medical implants. It is also used in the manufacture of alloys, such as tungsten carbide.
Tungsten is a relatively rare element, with an estimated abundance of 0.005% in the Earth’s crust. It is found in a variety of Minerals, including scheelite and wolframite.
Tungsten is a very important metal for a variety of applications. It is used in a variety of industries, including the electronics Industry, the automotive industry, and the aerospace industry.
Applications of LEDs
LEDs are used in a variety of applications, including:
- Indicator lights: LEDs are often used as indicator lights in electronic devices, such as computers, televisions, and appliances.
- Advertising signs: LEDs are often used in advertising signs, as they are bright and can be seen from a distance.
- General lighting: LEDs are increasingly being used in general lighting applications, as they are more efficient and durable than traditional light sources, such as incandescent bulbs and fluorescent tubes.
- Backlighting: LEDs are often used as backlights in LCD displays, as they are bright and energy-efficient.
- Traffic signals: LEDs are often used in traffic signals, as they are bright and can be seen from a distance.
- Headlights: LEDs are increasingly being used in headlights, as they are brighter and more energy-efficient than traditional light sources, such as halogen bulbs.
- Flashlights: LEDs are often used in flashlights, as they are bright and compact.
- Remote controls: LEDs are often used in remote controls, as they are small and can be seen in low-light conditions.
- Camera flashes: LEDs are often used in camera flashes, as they are bright and can be used to take pictures in low-light conditions.
- Medical devices: LEDs are used in a variety of medical devices, such as surgical lasers and dental curing lights.
- Industrial applications: LEDs are used in a variety of industrial applications, such as machine vision and process control.
Applications of IGBTs
IGBTs are used in a variety of applications, including:
- Power electronics: IGBTs are used in a variety of power electronics applications, such as inverters, rectifiers, and choppers.
- Motor control: IGBTs are used in a variety of motor control applications, such as AC motors, DC motors, and stepper motors.
- Power conversion: IGBTs are used in a variety of power conversion applications, such as solar inverters, wind turbine inverters, and UPS systems.
- Telecommunications: IGBTs are used in a variety of telecommunications applications, such as optical amplifiers, power amplifiers, and filters.
- Transportation: IGBTs are used in a variety of transportation applications, such as electric vehicles, hybrid vehicles, and Fuel Cells.
- Industrial automation: IGBTs are used in a variety of industrial automation applications, such as process control, motion control, and Robotics.
- Medical devices: IGBTs are used in a variety of medical devices, such as X-ray machines, MRI machines, and CT scanners.
LED
What is an LED?
An LED, or light-emitting diode, is a semiconductor device that emits light when an electric current is passed through it. LEDs are used in a variety of applications, including lighting, displays, and sensors.How do LEDs work?
When an electric current is passed through an LED, it creates a flow of electrons through a semiconductor material. This flow of electrons excites the electrons in the material, causing them to emit light. The color of the light emitted by an LED depends on the type of semiconductor material used.What are the advantages of LEDs?
LEDs have a number of advantages over other types of light sources, including:- They are more efficient than incandescent bulbs, meaning they use less energy to produce the same amount of light.
- They have a longer lifespan than incandescent bulbs, meaning they need to be replaced less often.
- They are more durable than incandescent bulbs, meaning they are less likely to break.
- They are dimmable, meaning they can be adjusted to produce different levels of light.
- They are available in a variety of colors, meaning they can be used to create different lighting effects.
What are the disadvantages of LEDs?
LEDs also have a few disadvantages, including:- They are more expensive than incandescent bulbs.
- They can flicker, which can be annoying to some people.
- They can emit blue light, which can be harmful to the eyes.
Insulated Gate Bipolar Transistor
What is an insulated gate bipolar transistor (IGBT)?
An IGBT is a type of transistor that is used to control power in electronic circuits. It is a combination of a metal-oxide-semiconductor field-effect transistor (MOSFET) and a bipolar junction transistor (BJT).How does an IGBT work?
When a gate voltage is applied to an IGBT, it creates a channel through which current can flow from the collector to the emitter. The amount of current that flows depends on the gate voltage.What are the advantages of IGBTs?
IGBTs have a number of advantages over other types of transistors, including:- They are more efficient than BJTs.
- They have a higher switching speed than MOSFETs.
- They are less susceptible to noise than MOSFETs.
What are the disadvantages of IGBTs?
IGBTs also have a few disadvantages, including:- They are more expensive than BJTs and MOSFETs.
- They have a higher saturation voltage than BJTs.
- They are more susceptible to thermal runaway than MOSFETs.
Properties of Tungsten
What is tungsten?
Tungsten is a chemical element with the symbol W and atomic number 74. It is a silvery-white metal that is hard and brittle. Tungsten is the heaviest element that is naturally occurring on Earth.Where is tungsten found?
Tungsten is found in a variety of minerals, including scheelite and wolframite. The largest producers of tungsten are China, Russia, and Bolivia.What are the properties of tungsten?
Tungsten has a number of properties that make it useful in a variety of applications, including:- It has a high melting point, which makes it suitable for use in high-temperature applications.
- It has a high tensile strength, which makes it suitable for use in structural applications.
- It has a high electrical resistivity, which makes it suitable for use in electrical applications.
- It has a high thermal conductivity, which makes it suitable for use in heat-sink applications.
What are the uses of tungsten?
Tungsten is used in a variety of applications, including:- Light bulbs
- X-ray tubes
- Electric motors
- Generators
- Welding rods
- Armor plating
- Cutting tools
- Jewelry
Question 1
A semiconductor device that emits light when an electric current is passed through it is called a:
(a) LED
(b) IGBT
(c) Tungsten
Answer
(a) LED
Question 2
An IGBT is a type of transistor that is used in power electronics. It is a combination of a bipolar junction transistor (BJT) and a field-effect transistor (FET).
Which of the following is not a characteristic of an IGBT?
(a) It is a three-terminal device.
(b) It has a high input impedance.
(c) It has a low output impedance.
(d) It can be used to switch high currents.
Answer
(b) It has a high input impedance.
Question 3
Tungsten is a chemical element with the symbol W and atomic number 74. It is a silvery-white metal that is hard and brittle. It is the heaviest of the naturally occurring Elements and the most corrosion-resistant metal.
Which of the following is not a property of tungsten?
(a) It has a high melting point.
(b) It has a high tensile strength.
(c) It is a good conductor of electricity.
(d) It is a good conductor of heat.
Answer
(c) It is a good conductor of electricity.
Question 4
Tungsten is used in a variety of applications, including:
(a) Light bulbs
(b) X-ray tubes
(c) Electric motors
(d) All of the above
Answer
(d) All of the above
Question 5
The melting point of tungsten is:
(a) 3422 °C
(b) 2710 °C
(c) 1900 °C
(d) 1538 °C
Answer
(a) 3422 °C