APPLIED PHYSICS ASSIGNMENT, Assignments of Physics

Download APPLIED PHYSICS ASSIGNMENT and more Assignments Physics in PDF only on Docsity!

APPLIED PHYSICS ASSIGMENT

NAME: MUHAMMAD USMAN

ROLL NO: ME-

SECTION: F (B)

COURSE CODE: PH-

SUBMITTED TO: MS AYESHA

APPLICATION LASER IN ENGINEERING FIELD

1. Welding and Cutting: The highly collimated beam of a laser can be focused to a microscopic dot of extremely high energy density for welding and cutting. The automobile industry makes extensive use of carbon dioxide lasers with powers up to several kilowatts for computer- controlled welding on auto assembly lines. 2. Communication: The lasers have significant advantages in communication because they are more nearly monochromatic and this allows the pulse shape to be maintained better over long distances when used in optical fiber. 3. Barcode Scanner: Supermarket scanners typically use helium-neon lasers to scan the universal barcodes to identify products. The laser beam bounces off a rotating mirror and scans the code, sending a modulated beam to a light detector and then to a computer which has the product information stored. 4. Surveying and Ranging: Helium-neon and semiconductor lasers have become standard parts of the field surveyor's equipment. A fast laser pulse is sent to a corner reflector at the point to be measured and the time of reflection is measured to get the distance. 5. Laser cooling: The use of lasers to achieve extremely low temperatures has advanced to the point that temperatures of 10 - K have been reached 6. Laser Spectroscopy: Laser spectroscopy has led to advances in the precision with which spectral line frequencies can be measured, and this has fundamental significance for our understanding of basic atomic processes.

current carrier are electrons. In PNP transistors, the majority current carrier is holes.

2. Field Effect Transistor (FET): Field Effect Transistors are made up of 3 regions, a gate, a source, and a drain. Different bipolar transistors, FETs are voltage-controlled devices. A voltage placed at the gate controls current flow from the source to the drain of the transistor. Field Effect transistors have a very high input impedance, from several mega ohms (MΩ) of resistance to much.) of resistance to much. 3. Heterojunction Bipolar Transistor (HBT): Heterojunction bipolar transistors (HBTs) are used for digital and analog microwave applications with frequencies as high as Ku band. HBTs can supply faster switching speeds than silicon bipolar transistors mostly because of reduced base resistance and collector-to-substrate capacitance. 4. Darlington Transistor: A Darlington transistor sometimes called as a “Darlington pair” is a transistor circuit that is made from two transistors. Sidney Darlington invented it. It is like a transistor, but it has much higher ability to gain current. The circuit can be made from two discrete transistors or it can be inside an integrated circuit. The circuit is helpful in audio amplifiers or in a probe that measures very small current that goes through the water. 5. Multiple-Emitter Transistor: A multiple-emitter transistor is specialize bipolar transistor frequently used as the inputs of transistor transistor logic (TTL) NAND logic gates. Input signals are applied to the emitters. Collector current stops flowing simply, if all emitters are driven by the logical high voltage, thus performing a NAND logical process using a single transistor. Multiple-emitter transistors replace diodes of DTL and agree to reduction of switching time and power dissipation.

6.Photo Transistor: Photo transistors are the transistors which operate depending on the light that means these transistors are light sensitive. The photo transistors have only 2 terminals instead of general 3 terminals. The transistor operates depending on the light. When the light sensitive area is dark then no current flows in transistor i.e. transistor is in OFF state. Do heavier objects fall more slowly than lighter objects? NO, heavier objects fall more faster than lighter objects because during the fall of object there are two force acting on a body. One of them is gravitational force which depend on surface area. Net acceleration given by a=g. Higher the air resistance on the object more delay in falling. Like feather have large surface area and mass is also less so it takes more time to reach the ground as feather is the lighter object. if lighter and heavier objects are in vacuum, they will fall at a same time because there is only gravitational force on them. How come in free fall you feel weightless even though gravity is pulling down on you? The reason you feel weightless is because there is no force pushing against you, since you are not in contact with anything. Gravity is pulling equally on all the particles in your body. This creates a sensation where no forces are acting on you and you feel weightless.