05-01-2018, 04:31 PM
Electromagnetic Induction
*The process of production of voltage (emf) across a conductor moving through a magnetic
field is called electromagnetic induction.
*Generators (Dynamo), Motors, Transformers, Microphones, Induction coil and Solenoids work on the principle of Faraday’s law of electro magnetic induction.
Mutual Induction
*Phenomenon of inducing a voltage (emf) in a coil by changing current in neighbouring coil is known as Mutual Induction.
*The coil in which voltage is induced is called secondary coil
*The coil in which current is changed is called Primary Coil.
*Instruments work on the principle of mutual induction - Transformers, Generators etc.
*Electric device that converts mechanical energy into electrical energy - Electric generator.
Lamps
*Incandescent lamps are filament lamps (Bulbs).
*Electric Bulb was discovered by
Ans : Thomas Alva Edison.
*Gas used to fill a filament lamp
Ans : Argon, Nitrogen etc.
*Lamp having highest energy efficiency
Ans : LED ' Lamp .
*In Fluorescent lamp, mixture of Mercury and Argon gas are filled.
*Examples of discharge lamps - Compact Fluorescent lamp (CFL), Tube lights, Vapour lamps
* Lifespan of filament lamp - 1000 hours ‘
*Lifespan of fluorescent lamps - 5000 hours
*Lamps used in advertisement boards - Neon vapour lamps
*The material used for making filament of bulb is Tungsten (W).
*Characterstics of LED, when compared to other lamps are energy efficient, low cost, longer life time, small size.
*Energy efficient means low consumption of energy.
*Nickel and Cadmium are used as electrodes in rechargable batteries of electric shaver, flash lights etc.
*Polygraph test machine detects and records the electrical variations in the body when a person tells lies.
*Electricity produced through water is termed as ‘Hydro Power’.
*Hydroelectric power is an electrical energy obtained from water-power which is used to drive a dynamo.
*National Energy Conservation Day?
Ans : December 14
Previous Question
*The purpose of Choke in the tube light is
Ans : to increase the voltage momentarily
Vapour Lamps & Colours
*Chlorine Vapour Lamp -Green
*Nitrogen - Red
*Hydrogen - Blue
*Sodium - Yellow
*Neon - range
*Mercury - White
