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Electricity & Megnetism

Types of electromagnetic waves and their uses,examples & properties

Electromagnetic waves are defined as:” Waves which requires no medium for transmission and which rapidly propagates through vacuum.”radio waves,television waves,X-rays light rays etc,are the examples of E.M waves. History In 1864 British physicist James Clark Maxwell formulated a set of equations known as Maxwell’s equations which explained the various electromagnetic phenomena. According to these equations, a changing magnetic flux creates ...

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Lenz’s Law of electromagnetic induction

What is Lenz’s Law of electromagnetic induction? Lenz’s law states that:”The direction of induced current is always so as to oppose the change which causes the current.” A mathematical expression of Faraday’s law of electromagnetic induction was derived as: ε = – N ΔΦ/Δt The minus sign in the expression is very important.It has to do with the direction of the ...

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What is transformer?-types,applications & working principle

“A transformer is an electrical device to change a given alternating emf into a larger or smaller alternating emf.”or “It is a static or stationary piece of apparatus that transfers electric power from one circuit to another having mutual inductance without changing the frequency.”A basic transformer is an electrical device constructed of two coils placed in close proximity to each ...

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5 band resistor colour code table and chart

Carbon resistors are most common in electronic equipment.They consists of a high grade ceramic rod or cone ( called the substrate on which is deposited a thin resistive film of carbon. The numerical value of their resistance is indicated by a colour code which consists of bands of different colors printed on the body of the resistor.The color used in ...

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structure of atom for class 9 and 11

what is Atom? “Atom is the smallest particle of an element that possesses the unique characteristics of that element.”All matter is composed of atoms;all atoms consists of electrons,protons, and neutrons except normal hydrogen,which does not have a neutron.Each element in the periodic table has a unique atomic structure,and all atoms within a given element have the same number of protons.At ...

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Potentiometer: definition,types and applications in circuit

What is potentiometer? “A potentiometer is a very simple instrument which can measure and compare potential differences accurately”.Potential difference is usually measured by an instrument called a voltmeter. The voltmeter is connected across the two points in circuits between which potential  differance is to be measured. It is necessary that the resistance of the voltmeter be large compared to the ...

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Different types of resistors with pictures,function and uses

A resistor is an electrical component with a known specific value of resistance.It is probably the most common component in all kinds of electronic equipment ranging from a small radio to a colour television receiver.As its name suggests ,a resister resists or opposes the flow of current through it.Resistance is necessary for any circuit to do useful work.In fact,without resistance,every ...

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electrical energy:definition,formula,unit,examples and uses

Electrical energy definition “Electrical energy is produced by moving electric charges commonly through a wire.”When charge moves from a higher electric potential to a lower potential,it delivers electric current.Thus,the process ,during which charges continuously move from a higher potential to a lower potential,becomes a continuous source of electrical.E. Examples of electrical energy Turbine runs generator to produce electrical energy when ...

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Ohm’s law formula with examples and problems

Ohm’s law states that: “The current flowing through a conductor is directly proportional to the potential difference across its ends provided the physical state such as temperature etc. of the conductor remains constant.” Ohm describes mathematically how voltage,current and resistance in a circuit are related.It is used in the equivalent form depending on which quantity you need to determine.In this ...

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electrical resistance in circuit with factors affecting on resistance

What is the definition of resistance in physics? “Resistance is the property of material that restricts the flow of electrons.”When there is current in a conductive material ,the free electrons move through the material and occasionally collide with atoms.These collisions cause the electrons to lose some of their energy,and thus their movement is restricted.This restriction varies and is determined  by ...

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