RL PHY 2 Flashcards by Pappu Roy

●Lux is the SI unit of: —

intensity of illumination

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●On a rainy day, small oil films on water show brilliantcolours. This is due to: —

Interference

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●Light travels at the fastest speed in: —

Vacuum

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●Light Emitting Diodes (LED) is used in fancyelectronic devices such as toys emit: —

Visiblelight

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●Rainbow is produced when sunlight fall on drops ofrain. Which of the following physical phenomenaare responsible for this? —

Refraction andInternal Reflection

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●All the rays coming from the source at the focus of aparabolic mirror are reflected as an intense:—

Parallel beam

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●Advanced sunrise and delayed sun- set found in thesky are due to the phenomenon of: —

Refractionof sunlight

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●Recording a permanent three dimensionalphotograph of a given single colour or a multi-colour is known as:—

Holography

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●What is colour of light related to: —

Frequency

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●What is viewed through an electron microscope?—

Structure of bacteria and virus

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The instrument which uses sound waves to measurethe depth of oceans is: —

SONAR

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●Which combination of colour is the most convenientduring day and night time? —

Red and Green

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●The speed of light with the rise in the temperature ofthe medium: —

Remains unaltered

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●What is the wavelength of visible spectrum? —

3900Angstrom-7600 Angstrom

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●Who measured the velocity of light first? —

Romer

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●An electron microscope gives higher magnificationthan an optical microscope because:—

thewavelength of electrons is smaller as compared tothe wavelength of visible light

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●Lamberts law is related to: —

Illumination

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●Danger signals are generally red as red light:—

Undergoes least deviation

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●A simple microscope consists of:—

A short focusconvex lens

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“●”“Short-sight”” in human eye can be corrected by usingproper:—”

Concave lens

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●What is the reason for twinkling of stars?—

Atmospheric refraction

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●Which colour is the complementary colour of yellow?—

Blue

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●A pond of water appears less deep due to: —

Refraction

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●The reason for a swimming pool to appear less deepthan the actual depth is: —

Refraction

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●The type of mirrors used in the headlamp of cars is:—

Parabolic Concave

●When a person walking in bright Sunlight enters adark room, he is not able to see clearly for a littlewhile because:—

The iris is unable to dilate thepupil immediately

●Spectacles used for viewing 3D films have: —

Polaroid

●According to the theory of relativity, which of thefollowing always remains constant?—

Velocity ofLight

●A colour-blind person cannot:—

distinguish betweencertain colours

●A photo-electric cell converts: —

Light energy toelectrical energy

●A concave lens always forms an image which is:—

Virtual and erect

●Lens is made up of: —

Flint Glass

●One can distinguish a telescope from a microscope byobserving: —

Length and size of the lens

●For a person having hypermetropia, the near point is:—

greater than 25 cm

●Light houses are places with powerful lights to: —

guide and warn the ships coming from differentdirections in the ocean

●Persistence of vision is the principle behind: —

Cinema

●The light rays used for eliminating bacteria are:—

ultraviolet radiation

●A person wears spectacles with concave lenses. Itmeans that normally (when not using glasses), theimage of distant objects is focussed in his eyes: —

in front of the retina

●Myopia is the same as: —

Near sightedness

●A microscope used in pathological laboratoriesforms:—

Magnified, virtual and inverted image

●The magnifying power of an astronomical telescopecan be decreased by:—

Increasing the focal lengthof the eyepiece

●The owl can see most clearly in the dark because:—

ithas large eyes with orbs directed forward, givingit binocular sight

●Night photography and photography in mist and fogare possible using: —

Infra-red radiation

●The blue colour of water in the sea is due to:—

absorption of other colours except blue by watermolecules

●Rainbow is seen after rain because of hangingmolecules of water which act as: —

Prisms

●In sunlight, a rose appears red. In green light, thesame rose appears: —

Black

●The sparkling of a diamond is due to:—

TotalInternal Reflection of light

●Parabolic mirrors are used in: —

Car headlights

●The sharpness of a television image is termed as its:—

Resolution

●The final image in a simple microscope is:—

Virtual,magnified and erect

●Hypermetropia or long sight can be corrected byusing:—

Convex lenses

●An optically plane surface reflects a beam of light:—

as diffused beams in all directions

●A periscope works on the principle of:—

Totalinternal reflection

●A rear-view mirror for driving is: —

Convex

●The part of the eye having the largest refractive indexis:—

Lens

●A man cannot see clearly beyond 10 metres. Thedisease he suffers from is: —

Myopia

●Energy in reflected light:—

increases with increase inangle

●Which colour of light shows maximum deviationwhen passed through a prism? —

Violet

●When a light wave is reflected from a mirror, there isa change in its: —

Amplitude

●Which type of mirror is used in the head lights ofvehicles?—

Concave mirror

●Shaving mirror is: —

Concave

●Magnifying glass is basically a: —

Convex lens

●White clothes are cooler than black ones becausethey:—

reflect all the light that reaches them

●The primary colours in photography are:—

Red,Blue, Yellow

●A concave lens always forms: —

a virtual image

●A water tank appears shallow when it is viewed fromtop due to:—

refraction

●For a ray of light to suffer total internal reflection, ithas to pass from: —

air to water

●When air rises, it is cooled by: —

Expansion

●Collision of metal atoms with each other releases:—

Heat energy

●The temperature of a metal wire ____ ,when anelectric current is passed through it. —

Rises

●Low temperatures (cryogenics) find application in:—

Space travel, surgery and magnetic levitation

●A stick is dipped in water in a slanting position. Ifobserved sideways, the stick appears:—

Short andbent at the surface of water.

●A piece of copper and a piece of glass are heated tothe same temperature. When touched, thereafter,:—

the copper piece appears hotter than the glasspiece.

●The boiling point of ____ decreases as the amplitudeincreases. —

Water

●When water is heated from 0 degree celsius to 10degree celsius, its volume:—

first increases andthen decreases

●A hollow sphere of radius R, a hollow cube of side Rand a thin circular plate of radius R, made up ofthe same material, are all heated to 200 C aboveroom temperature. When left to cool in the room,which of them will reach the room temperaturefirst? —

Sphere

●With the increase of temperature, the viscosity ofglycerine:—

Increases

●On a cold day when a room temperature is 150 C, themetallic cap of a pen becomes much colder thanits plastic body, though both are at the sametemperature of 150 C, because:—

metals are goodconductor of heat

●When a ring of metal is heated what happens to itshole?—

It expands

●When heated from 0 degree to 10 degree celsius, thevolume of a given mass of water will:—

Decreaseand then will increase

●The best conductor of heat among the following is:—

Mercury

●Clear nights are colder than cloudy nights because of:—

Radiation

●A gas thermometer is more sensitive than a liquidthermometer because a gas: —

Is easy to obtain

●The metal used for the manufacture of heatingelements provided in electric iron is —

Nichrome

●'Cryogenics' is a science dealing with: —

Lowtemperatures

●If the temperature of a place increases suddenly, therelative humidity: —

Decreases

●Why two thin shirts can keep us warmer than a singlethick shirt in winter?—

Air layer between twoshirts behaves like insulating media

●What changes will happen to a bowl of ice and waterkept at exactly zero degree celsius? —

No changewill happen

●Curie point is the temperature at which:—

A metalloses magnetic properties

●Cloudy nights are warmer compared nights becauseclouds mainly:—

reflect back the heat given byearth

●A metal plate with a circular hole at the centre isheated. What will happen to the area of the hole?—

Increase

●Lakes freeze in cold countries in winter, leaving thewater underneath at: —

4 degree celsius

●Refrigeration is a process which:—

slows down thebacterial growth

●Air coolers are more suitable for: —

hot and dryclimate

●When hot-water is sprinkled on a hotter glasstumbler, it breaks because: —

glass suddenlycontracts

●If there is a circular hole in a metal plate, whathappens to the radius of the hole when the plate isheated?—

It increases

●Mud houses are cooler in summers and warmer inwinters as compared to brick houses because:—

Mud is a bad conductor

●In heating frozen foods in sealed pouches inmicrowaves, why do you first poke holes in thepouch? —

To prevent the steam pressures frombursting open the pouch

●Steam at 1000 Celsius causes more severe burns thanwater at 1000 Celsius because:—

Steam has latentheat of vaporization

●During the hot weather, the fan produces a feeling ofcomfort. This is because: —

our perspirationevaporates rapidly

●In a diesel engine, the high temperature needed toignite the fuel is achieved by: —

compressing airin the cylinders

●How much mechanical work must be done tocompletely melt 1 gram of ice at 00 celsius? —

80J

●Heat stored in water vapour is: —

Latent Heat

●A copper disc has a hole. If the disc is heated, the sizeof the hole: —

increases

●Water boils at a lower temperature in the hillsbecause: —

there is a decrease in air pressure onthe hills

●The temperature which has the same reading on bothFahrenheit and Celsius scales, is: —

Minus 40degree celsius

●A body absorbs heat most if it is: —

black and rough

●The temperature of boiling water in a steam enginemay be high because of: —

there is high pressureinside the boiler

●The water from a hand pump is warm in winterbecause:—

The temperature inside the earth ishigher than the atmospheric temperature

●Water is used in hot water bags because:—

It hashigh specific heat

●Which device is used in D.C. circuits?—

Transformer

●Domestic electrical wiring is basically a:—

parallelconnection

●At the present level of technology available in India,solar energy can be conveniently used to: —

Supply hot water to residential buildings

●A fuse is used in mains electric supply as a safetydevice. Which one of the following statementsabout the fuse is correct?—

It must have a lowmelting point

●In a motor car battery, the voltage is usually: —

12 V

●Fluorescent tubes are fitted with a choke. The chokecoil:—

Reduces current in the circuit

●Two wires have their lengths, diameters andresistivity all in the ratio of 1:2. If the resistance ofthe thinner wire is 10 ohm, the resistance of thethicker wire is: —

10 ohm

●The frequency of alternating voltage supplied is: —

50 Hz

●What is the order of magnitude of electric resistanceof the human body (dry)? —

106 ohm

●Basically domestic electric wiring is a:—

combinationof series and parallel connections

Large transformers, when used for some time, becomevery hot and are cooled by circulating oil. Theheating of the transformer is due to: —

both theheating effect of current and hysteresis loss

●Metals are good conductors of electricity because:—

They contain free electrons

●Rectifiers are used to convert: —

Alternating currentto Direct current

●Point A is at a lower electrical potential than point B.An electron between them on the line joining themwill:—

Move towards B

●Suitable impurities are added to a semiconductordepending on its use. This is done in order to:—

increase its electrical conductivity

●Substances which offer no resistance to the flow ofelectricity are known as: —

Superconductors

●In which of the following industries is mica used as araw material? —

Electrical

●One should not connect a number of electricalappliances to the same power socket because:—

this can damage the domestic wiring due tooverloading

●Transformer is used to:—

Convert low A.C voltage tohigh voltage

●Electrical energy can be easily and cheaply changedfrom one voltage to another by a ____ withoutmuch loss of energy.—

Transformer

●The filament of electric bulb is generally made oftungsten because: —

melting point of tungsten ishigh

●Which term is used to denote materials with a muchhigher conductivity than insulators but a muchlower conductivity than metals? —

Semiconductor

●In electronics what comes under tank circuit?—

Capacity and inductance

●The fundamental scientific principle in the operationof battery is: —

Dissociation of electrolytes

●Good conductor of electricity is: —

Graphite

●Electrostatic precipitator is used to control thepollution of:—

Thermal

●When the main switch of the house is put off itdisconnects the: —

live wire and the neutral wire

●A multimeter is used to measure:—

Current, Voltage,resistance

●A device used for converting Alternating Currentinto Direct Current is called: —

Rectifier

●The metal used to make lightning conductors is: —

Copper

●Superconductors are those elements:—

whoseresistance falls almost to zero at very lowtemperatures

●Alternating current is converted into direct currentby:—

Rectifier

●Which of the following circuit elements is used to'block' DC in an electronic circuit? —

Capacitance

●The fuse in our domestic electric circuit melts whenthere is a high rise in: —

Current

●The device used to change the speed of an electric fanis:—

Regulator

●Pure water is bad conductor of electricity because itis:—

feebly ionized

●When electricity is transmitted over long distances:—

There is less wastage of energy

●Electric current in a metal wire is due to the flow of:—

Electrons

●After long periods of use, a grey spot develops on theinside of a bulb. This is because: —

The tungstenfilament evaporates and collects there

●Lightening is caused due to: —

electric discharge

●The device which transfer the signal from lowresistance region to high resistance region is: —

Transistor

●A bird sitting on a high tension electric wire does notget electrocuted because:—

it does not form aclosed path for the flow of current

●If a copper wire is increased to double its length, itsresistance will become: —

Double

●Superconductor is the conductor whose ___ is zero.—

Resistance

●A device which is used to limit the current in anelectrical circuit is called: —

Fuse

●The earth wire of a cable is connected to:—

the fuseof the appliance

●Water cannot be used to extinguish fire caused byelectric current, because:—

it may causeelectrocution

●The metal whose electrical conductivity is more, is:—

Silver

●Moving electric charge produces: —

Magnetic field

●The S.I. unit of electric charge is: —

Coulomb

●The best material for the core of a transformer is:—

Soft iron

●Metal tea pots have wooden handles because:—

itprevents electric shock

●The best conductor of electricity among the folloiwngis :—

Silver

●Electromagnetic theory was proposed by: —

Maxwell

●Magnetism at the centre of a bar magnet is: —

Zero

●When a vehicle passes TV reception gets distorted.This is because:—

Spark plug creates

●Magnetism in materials is due to:—

Circular motionof electrons

●In the process of magnetization of a bar:—

The entirebulk of the bar gets magnetized

●The scientist who first sent electromagnetic waves todistant places is: —

Thomas Alva Edison

●When a bar magnet is cut into two equal halves, thepole strength of each piece: —

Remains the same

●In MRJ machine, which one of the following is used?—

Magnetic Wave

●Tape Recorder should not be kept near which one ofthe following things? —

Magnet

●The width of depletion layer of a P-N junction:—

isincreased under reverse bias

●Modern movie songs released are the best in qualityof sound. The rich quality of sound is due to whichone of the following?—

Consists of manyharmonics

●When the frequency distribution is normal:—

Mean,mode, and median are identical

●For reproducing sound, a CD (Compact Disc) audioplayer uses a: —

Laser Beam

●Which waves are produced by rapidly oscillatingelectrical current?—

Radio waves

●To detect the over-speeding vehicles, police use theDoppler effect of reflected: —

Short radio waves

●What is the term for the form of amplitude variationsin the transmitted signal due to atmosphere,industries etc?—

Noise

●Which transmission of music is a very good qualitymusic because the atmospheric or man madenoises which are generally frequency variationscan do little harm?—

FM Transmission

●Sound waves in air are: —

Longitudinal

●RADAR is used for: —

detecting and locating theposition of objects such as aeroplanes

●Sound of frequency below 20 Hz is called: —

Infrasonic

●The melodious effect on our ear produces by thecombination of two or more notes of the modernpop songs is called:—

Concord

●Sound travels with a different speed in media. Inwhat order does the velocity of sound increase inthese media?—

Air, Water and Iron

●Sound travels at the fastest speed in: —

Steel

●Sound produced at a point is heard by a person after5 second, while the same sound is heard byanother person after 6 seconds. If the speed ofsound is 300 m/s, what could be the maximum andminimum distances between the two persons?—

3.3 km, 0.30 km

●Intensity of sound at a point is ____ its distance fromthe source. —

Inversely proportional to the squareof

●Supersonic plane fly with the speed:—

greater thanthe speed of sound

●Mach number is used in connection with the speed of:—

aircraft

●Intensity of sound has an: —

Object existence

●What is found in frequency modulation?—

Fixedfrequency

●Two waves each of amplitude 1.5 mm and frequency10 Hz are travelling in opposite direction with a speed of 20 mm/s. Thedistance in mm between adjacent nodes is: —

1.0

●A person standing on a railway platform listens to thewhistles of arriving and departing trains. Thewhistle heard is:—

of higher pitch when trainarrives

●Why are we able to hear short wave broadcasts in abetter way than long wave broadcasts?—

Shortwaves are more energetic than long waves

●Longitudinal waves cannot travel through: —

Vacuum

●Submerged objects can be located using: —

SONAR

●A decibel is: —

A measure of sound level

●In a Laser (say neon laser) all the atoms emit the lightwaves of:—

Same frequency, same amplitude andsame phase

●What is the full form of 'AM' regarding radiobroadcasting?—

Amplitude Modulation

●The propagation of sound waves in a gas involves: —

Adiabatic compression and rarefaction

●If input frequency of a full wave rectifier be n, thenoutput frequency would be: —

●Noise is measured in: —

Decibel

●The bats can fly in the dark because:—

they generateultrasonic sound waves

●The frequency of ultrasound wave is typically:—

Below 20 kHz

●The sound produced by a bat is: —

Ultrasonic

●The sounds having a frequency of 20 Hertz to 20,000Hertz are known as: —

Audible sounds

●When a vibrating tuning fork is placed on a table, aloud sound is heard. This is due to: —

Forcedvibrations

●The distance between node and adjacent anti-node is30 cm, the wavelength is: —

60 cm

●The velocity of sound in air:—

decreases withdecrease of temperature

●The audio signals of TV are: —

Frequency modulated

●To measure the speed of an approaching car, a policeofficer shines: —

radio waves on it

●Waves that are required for long distance wirelesscommunication are: —

Radio waves

●These waves cannot be transmitted through vacuum:—

Sound

●Speed of sound in air is unaffected by change in:—

Pressure

●Negative feedback in amplifiers:—

increasesbandwidth and decrease noise

●Permissible noise level at Residential area duringnight time is:—

45 dB (A)

●The pitch of sound depends on its:—

Frequency

●The technique used to transmit audio signals intelevision broadcasts: —

Frequency Modulation

●When the same note is played on a sitar and a flute,the sound produced can be distinguished fromeach other because of the difference in: —

Qualityonly

●The distance between two consecutive crests in awave train produced in a string is 5 cm. If 2complete waves pass through any point persecond, the velocity of the wave is:—

10 cm/sec

●The speed of a wave in a medium is 760 m/s. If 3600waves are passing through a point, in the mediumin 2 minutes, then its wavelength is: —

25.3 m

●The number of waves contained in unit length of themedium is called: —

Wave Number

●The frequency of a sound wave is n and its velocity isv. If the frequency is increased to 4n the velocity ofthe wave will be:—

●When sound waves travel from air to water, which ofthe following remains constant? —

Frequency

●Sound waves have the following frequencies that areaudible to human beings: —

5000 c/s

●It is possible to distinguish between the transverseand longitudinal waves by studying the propertyof: —

Polarization

●A pulse or a wave train travels along a stretchedstring and reaches the fixed end of the string. Itwill be reflected back with: —

A phase change of180° with velocity reversed

●A medium can carry a longitudinal wave because ithas the property of: —

Elasticity

●The waves in which the particles of the mediumvibrate in a direction perpendicular to thedirection of wave motion is known as: —

Transverse Wave

●The type of waves that can be propagated throughsolid is:—

Transverse and Longitudinal

●A tuning fork produces waves in a medium. If thetemperature of the medium changes, then whichof the following will change? —

Wavelength

●A travelling wave passes a point of observation. Atthis point, the time interval between successivecrests is 0.2 seconds and the frequency is: —

5 Hz

●Which one among the following lasers is used incancer treatment? —

CO2 laser

●A simple machine helps a person in doing:—

thesame amount of work with lesser force

●The working principle of a washing a machine is:—

Centrifugation

●The working principle of a washing machine is:—

Centrifugation

●Cryogenic engines find application in: —

RocketTechnology

●The working of the quartz crystal in the watch isbased on the:—

Piezo-Electric Effect

●The instrument that measures and records therelative humidity of air is: —

Hygrometer

●Instrument used to measure the force and velocity ofthe wind is: —

Anemometer

●Which of the following is used for accuratelymeasuring very small time intervals? —

Atomicclocks

●The instrument for measuring intensity ofearthquakes is called: —

Seismograph

●The instrument used to measure the speed of thewind is:—

Anemometer

●Bolometer is used to measure: —

Temperature

●A new technology which provides the ability to createan artificial world and have people interact with itis called:—

Virtual Reality

●The material used in the fabrication of a transistor is:—

Silicon

●The device which converts sound energy intoelectrical energy is called: —

Microphone

●A Photostat machine works on: —

electrostatic imagemaking

●Forged documents are detected by:—

Ultra-violetrays

●The important unit of a microprocessor is:—

ALU,array of registers and control unit

●Flight Recorder is technically called: —

Black Box

●An instrument is used to measure humidity is:—

Hygrometer

●An instrument that records earthquakes is:—

Seismograph

●Electrostatic precipitator is used to control:—

Airpollutants

●Velocity of sound in air does not depend on:—

Pressure of air

●Glass can be etched or scratched by:—

Diamond andHydrofluoric Acid

●What is fast becoming a very important field ofactivity in India? —

Information technology

●The correctly matched lists are: — High Speed:Mach; Wavelength:

Angstrom; Pressure: Pascal;and Energy: Joule

●What is the term for a plastic card with an embeddedmicrochip? —

Smart Card

RL PHY 2 Flashcards

(260 cards)