Physics Quick Bites : One Liner for Competitive Exam 2025

Physics Quick Bites: One Liner for Competitive Exam 2025. It is in continuation of the previous notes posted on 23 May 2025. Taken from notes posted from different links on Google.

Physics

• If the mass of a person is 60 kg on the surface of earth then the same person’s mass on the surface of the moon will be           60kg
• Which units is used for measuring the amount of a substance     Mole
• Through which of the mediums can sound NOT travel          Vacuum
• The Theory of Relativity is associated with        Albert Einstein
• According to which law, at constant temperature, the volume of a gas is inversely proportional to pressure          Boyle’s Law
• What is the SI unit of force Newton
• Which branch of physics deals with properties of fluids at rest     Hydrostatics
• What is the other name of Newton’s first law of motion          Law of inertia
• The momentum of an object of mass ‘M’ moving with a velocity ‘v’ is given by         Mv
• Which of the two colours of spectrum forms the extremes                     Violet and Red
• What is the momentum of an object having mass of 14 kg and velocity 28 m/s –392 kg-m/s (p = mv)
• The three laws of motion were proposed by                Newton
• Which type of mirror is used by dentists to see large images of patient’s teeth- Concave mirror
• Which devices is used to measure the atmospheric pressure        Barometer
• The ability of the eye to focus on both, near and distant objects, by adjusting its focal length, is called the Accommodation of the eye
• Modern electrical generator works on principle of          Electromagnetic Induction
• Travellers in deserts often tend to have an optical illusion of a sheet of water where none actually exists. What is this called                Mirage
• Who invented the modern mercury thermometer with a standardised scale  Daniel Gabriel Fahrenheit
• The ability of medium to refract light is also expressed in terms of its              Optical density 
• The center of the reflecting surface of a spherical mirror is a point called                  Pole
• Who provided the basic theory about the nature of matter           John Dalton
• What is the SI unit of power of a lens called Dioptre
• Which British physicist was awarded the Nobel Prize in Physics in 1906 for his work on discovery of electrons J J Thomson

• The persistence of sound in an auditorium is the result of repeated reflections of sound and is called Reverberation
• In 1752, which American scientist shows that lightning and the spark from your clothes are essentially the same phenomena Benjamin Franklin
• A voltmeter  is an instrument which can detect the presence of Potential difference
• The instrument used to measure current is called Ammeter
• Which is NOT generally the properties of non-metal –Conductors
• Which instrument is used to show the direction of flow of current in a circuit Galvanometer
• Which is used to detect cracks and flaws in metal blocks – Ultrasound
• Which sub-atomic particle was discovered by J Chadwick –Neutron
• The SI unit of sound was named in honour of which physicist –Heinrich Rudolf Hertz
• Who proposed the laws of planetary motion Johannes Kepler
• Albert Einstein was awarded the Nobel Prize for _____in 1921 Photoelectric effect
• Name the British chemist who presented his atomic theory in 1808, on conservation of mass and law of definite proportions, which was a turning point in the study of matter John Dalton
• What is the SI unit of resistance – Ohm
• A microphone converts – Sound energy into electrical energy
• The speed of sound _____as it passes from solid to gaseous medium – Decreases
• Which devices is used to convert alternating current into direct current –Rectifier
• Automobiles are fitted with a device that shows the distance  travelled –Odometer
• Which units is used to measure the intensity of sound -Decibel
• Which instruments is used to measure wind speed –Anemometer
• We hear others speaking to us from adjacent rooms due to ____of sound waves – Diffraction
• Give me a place to stand and I will move the world . which famous scientist said these words – Archimedes
• What is measured in ‘joules’ –Energy
• The lens which is thin in the middle and thick at its periphery is called a – concave lens
• Rockets work on the principle of conservation of – Momentum
• A light-year is a unit of –Distance
• Which type of mirror is used by dentists to see large images of patient’s teeth –Concave mirror
• Which was discovered by Henri Becquerel –Radioactivity
• Which colour deviates the least when light passes through a prism –Red

• Who formulated the equation E=mc2      – Albert Einstein
• Newton is the unit to measure      -Force
• The phenomenon of ‘dispersion of light’ into its seven constituent colours was discovered by   Isaac Newton  in 1666 .
• Which energy of the wind does a windmill use   -Kinetic energy
• If a lens has a focal length of 25 cm, what will be the power of that lens –  4D
• Who was the founding director of BARC Mumbai         -H J Bhabha
• The rate of doing work is called power. The unit of power is-Watt  
• The force of attraction applied between molecules of the same substance is called   – Cohesive force
• For communication, elephants can make noises as loud as 103 decibels but they often use low frequency sound, some of which is passed through the ground. These sounds are called               –Infrasound
• If a person has difficulty in seeing distant objects clearly, what condition is he suffering from and how can it be corrected    – Myopia, using concave lens 
• What is the equation for Newton’s second law of motion          – F=ma
• Shadows are formed when Opaque objects come in the path of light.
• The rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of the force. This rule is known as – Newton’s second Law of  Motion
• Who was the first person to obtain a spectrum by passing light through a prism                  -Isaac Newton
• The boiling point of liquid nitrogen is =>  -196 deg celcius
• Who is considered as the ‘Father of Nuclear Physics   – E. Rutherford 
• What is the speed of sound in air            -343 m/sec
• Visible Radiation was discovered by       –Issac Newton
• The SI unit of ‘magnetic flux’ is     -Weber
• The atomic number of an element is the number of            Protons        in the nucleus of each atom of that element
• Which types of light carries a signal from a television remote to the device it controls     – Infrared
• Who noticed the deflection of the compass needle every time current was passed through the wire         -Hans Christian Oersted
• The friction in liquids is called       – Viscosity
• Name an example of a thermonuclear fusion reaction  –Hydrogen bomb
• The repeated reflection that results in the persistence of sound is called – Reverberation
• The technology that uses the reflection of ultrasound waves to produce images of the heart is known as      – Echocardiography
• A spring balance is a device commonly used for measuring the  Force  acting on an object .
• The value of ‘g’ is maximum at     – Poles
• Long Radio waves were discovered by   –Marconi
• Blood pressure is the force –  That blood exerts against the wall of a vessel
• Which can produce a virtual image larger than the object          –Concave mirror
• Which equipment is used to transform mechanical energy into electrical energy         – Dynamo
• What is the unit of measurement used for measuring the energy requirements of the human body –Calories
• The ten percent law of energy transfer was given by    –Raymond Lindeman
• Light travels in a      – Straight line
• The unit of Force is- Kgms-2 (Newton )
• The work done by force acting on an object is equal to the amount of force multiplied by the distance travelled in the direction of the force. Which is a unit of work         –Joule
• What is the fastest seismic waves           – Primary waves
• What is the SI unit of radioactivity –Becquerel
• What is the SI unit of pressure      –Pascal
• Which device is used to identify the presence of electric charge on an object-Electroscope
• Rainbow is a natural phenomenon which shows          – Dispersion
• What does LED stand for in semiconductor electronics          –Light emitting diode
• Who discovered the law of planetary motion      – Kepler
• How many laws of motion were given by Issac Newton          –Three laws
• What is the full form of MCB         – Miniature Circuit Breaker
• A fuse wire is always connected to the    –Live wire
• Metal commonly used for making an electromagnet     – Iron
• The weight of a body is      – Maximum at the poles
• An ice cube is floating on the surface of water: How will the water level be affected by melting of this ice cube – Water level will remain the same
• A moving electric charge produces         – Both electric and magnetic field
• Instrument used to store the electric charge is known as          – Capacitor
• Distance is a –Scalar quantity
• Displacement is a    –Vector quantity
• Growth of the baby in the uterus is found using            – Ultrasound
• Tungsten is used for the manufacture of an electric bulb because        – it has a very high melting point
• SI Unit of radioactivity source       – Becquerel
• Television was invented by           – J. L Baird
• The lens used to rectify long sight is       – Convex
• Ball pen works on the principle of – Capillarity and surface tension
• Water stored in a dam possesses           – Potential energy
• The basic process taking place in nuclear reactors is   –Fission
• An electric generator actually acts as      – a converter of energy
• ‘parsec’ is the unit measurement of         – Astronomical distance
• 1 Astronomical Unit (AU)    – 1.496 x 1011 m
• 1 Parsec       –3.086×1016 m
• Astronomical Unit is the mean distance of         -The centre of the sun from the centre of the earth.
• The acceleration in a body is due to        -Unbalanced force
• The Screw Gauge is an instrument to measure the dimensions of very small objects up to     – 0.01 mm.
• A boat will submerge when it displaces water equal to its own – weight
• The splitting of different colours of light in a prism is     – Dispersion of light
• Surface tension in a liquid is due to   – Cohesive force between molecules
• The least distance of distinct vision is     – 25cm
• Woollen clothes keep the body warm as – wool is a bad conductor of heat
• The temperature of a liquid is 32oF.  what is its temperature in Celsius scale        –0oC
• While catching a ball, a player pulls down his hands to lower the – momentum
• The sky seems blue as of – Scattering of light
• In which form is the supplied heat energy stored during change in temperature of substance                 – kinetic energy
• Dynamo is a device for converting          – Mechanical energy into electrical energy
• When milk is churned, the cream from it is separated due to           – Centrifugal force 
• ‘short-sight’ in human eye can be corrected by using proper           – concave lens
• A falling drop of rainwater acquires the spherical shape due to           – Surface Tension
• When a body is taken from earth to moon         -weight changes but mass remains same
• The oil in the wick of an oil lamp rises up due to          – Capillary action
• Sound waves in air are –  Longitudinal
• A periscope works on the principle of      -total internal reflection 
• Heat stored in water vapour is      – latent heat
• Shaving mirror is     – Concave
• An instrument used to measure humidity is       – Hygrometer
• A light year is a unit of – distance
• Hydraulic brakes in automobile work on – Pascal’s principle
• Milk is a colloidal system in which – Fat is dispersed in water
• Neutrons are slowed down in a nuclear reactor by       – moderator
• The unit of electrical power is       – Watt or joule per second.
• Electric current in a metal wire is due to the flow of      -Electrons
• The value of acceleration due to gravity (g) minimum at          – Equator 
• The value of acceleration due to gravity  -9.8 m/s2
• The device used for locating submerged objects under sea is -sonar  
• The distance from the pole to the focus is called          – Focal length
• What is the nature of eye lens of human eye     – Convex in nature.
• Focal length of eye lens can be adjusted by      – Ciliary muscles
• The speed of the sound remains unchanged by the increase or decrease of –pressure.
• SONAR stands for   -Sound Navigation And Ranging
• When a body falls freely under gravity then the work done by the gravity is –positive
• The sum of the kinetic and potential energies of an object is called its –mechanical energy
• Sound cannot travel through         – vacuum
• What is the SI unit of angular velocity     -Radian /second
• What is the SI unit of Weight        – Newton
• What is the SI unit of Mass           – kilogram
• What is the SI unit of Area  –square meter
• The SI unit of pressure is   – Pascal
• The domestic electricity in India is an ac with a frequency of       –50Hz
• Thickness of a cricket ball is measured by         – Vernier scale.
• Least count of Vernier calliper is   – 0.01 cm
• Bi-focal lens are required to correct        – Presbyopia
• The Rate Of Flow Of Electric Charges is Called           – Electric Current
• The rate of change of velocity is   – Acceleration
• The rate of change of displacement with time is called           -Velocity
• A device that is used to break an electric circuit is called a        -Switch.
• The resistance of the wire varies inversely as    – Area of cross section.
• Kirchhoff’s second law is based on the law of conservation of        -Energy
• Kirchhoff’s first law is based on the         -Conservation of charge
• SI unit of heat is the           -Joule (J)
• The power of a lens is        –The reciprocal of its focal length (P=1/f).
• What is the SI unit of heat energy – Joule 
• Kelvin (K) is the unit of measurement of  – Temperature
• Push or pull of an object is called  -Force
• What is the SI unit of frequency    – Hertz
• What is the other name of Galileo’s law of falling bodies          – Newton’s first law
• The spectrum of light was first explained by      – Isaac Newton
• Who received the very first Nobel Prize in Physics in 1901 for his discovery of X-rays              – William Rontgen
• Mirror used by dentist to see large image of teeth of patients is     – Concave mirror
• What is the SI Unit of Inductance  – Henry
• The weight of an object is directly proportional to its    -Mass
• Weight of the object on the moon is -1/6^th  of its weight on the earth
• Newton’s law of universal gravitation       –F=GMm/d2
• Propulsion of rockets is based on the-    – Law of conservation of linear momentum as well as Newton’s third law of motion.
• The third law of motion states——— “To every action, there is an equal and opposite reaction and they act on two different bodies”
• The first law of motion is stated as          – “An object remains in a state of rest or of uniform motion in a straight line unless compelled to change that state by an applied force “
• Lactometers which are used to determine the    – Purity of a sample of milk
• The barometer was invented by    – Torricelli
• Supersonic air plane creates a shock wave called        – Sonic Boom
• With both eyes open, a person’s field of view is about  –180o
• The Ionization power is maximum for      – Alpha particle
• Who discovered radioactivity        – Henri Becquerel
• The mass per unit volume is called         – Density
• Which instrument is used for viewing the sun    – Helioscope
• A ball rolling on the ground slows down and finally stops. This is because of – Friction
• Objects float on water based on   – Archimedes principle
• Velocity of sound in air does not change with the change of – Pressure of air
• The density of gas is maximum at           – Low temperature high pressure
• Why is it difficult to breathe at higher altitudes   – Due to low air pressure
• The strongest force in nature is    – Nuclear force
• Which lenses should be used to correct the defect of astigmatism  – Cylindrical lens
• An oil drop spreads over water because – Surface tension of oil is much smaller than that of water
• The device which convert AC to DC is    – Rectifier
• Knot is a measure of          – The speed of ship
• Decibel is the unit used for           – Intensity of sound
• Energy is continuously created in the sun due to         – Nuclear fusion
• The bats can fly in the dark because       – They generate ultrasonic sound waves
• What is the unit of electric resistance      – Ohms
• Rate of change of momentum is   – Force
• Which mirror is used in the headlights of cars    – Concave
• Optical fibres are based on the phenomenon of     – Total internal reflection
• Brilliance of diamond is due to      –Total internal reflection
• The formula for potential energy   -mgh
• The formula for kinetic energy      -1/2mv2
• The star appear shifted from their actual position due to the phenomenon of – Refraction of light
• To an astronaut in space, the sky will appear to be      -Black
• Escape velocity of moon is           – 2.38km/s
• Escape velocity of earth is            – 11.22km/s
• The SI unit of acceleration due to gravity is       – m/s2
• What is the value of gravity on the moon           – 1.62 m/s².
• What is the mathematical expression of Mass energy equation        – E=mc2
• What is the mathematical expression for the Newton’s Second law of Motion         –  F=ma
• What is the SI unit of the Electric capacity of a conductor          – Farad
• Which law states that ‘the ratio of sine of angle of incidence to the sine of angle of refraction is a constant          – Snell’s law
• Which law states that the stress imposed is directly proportional to the strain under elastic limit        – Hook’s Law
• Which instrument is used to measure the Relative Density         -Hydrometer
• Snell‟s law of refraction      – Sin i/ sin r=constant
• The Shortest distance covered by the body in a definite direction is known as         – Displacement
• While jumping from a slowly moving bus, one must run for a short distance in the direction of motion due to    – Inertia
• Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight – Isaac Newton
• Which colour of the white light suffers maximum bending when it passes through a glass prism     – Violet
• The loudness of the sound is measured in terms of     – Decibel
• What is the minimum distance from a sound reflecting surface to hear an echo     –17 m
• What is the S.I unit of Magnetic Flux Density     – Tesla
• The electrical resistance of insulators is            – infinitely high
• What is the upward force exerted by water called        – Buoyant force
• Ice floats on water because its density is           – Less than water
• The capacity to do work is called – Energy
• The instrument used to measure the rotation speed of a shaft is called  – Tachometer
• Least distance of distinct vision for normal eye is         – 25cm
• Instrument is used to measure electric current? – Ammeter
• What is the unit of pressure          – Pascal
• The SI unit of electric charge is    – coulomb
• A person holding a pen in his left hand sees his reflection in the mirror holding the pen in his right hand. This is due to which of the following phenomena?     – Lateral inversion
• The resistance of a conductor is inversely proportional to its       – Area of cross section (R∝ 1/A)
• 1 kWh           -3.6X106 J
• What is the unit of relative density           -It has no unit
• The instrument for measuring intensity of earthquake is called – Seismograph
• Plant growth measured by using             – Crescograph
• Who discovered Electron?—– J.J. Thomson
• The washing machine works on the principle of           -Centrifugation
• A liquid disturbed by stirring comes to rest due to        -Viscosity
• Which instrument is used to measure altitudes in aircraft’s        – Altimeters
• Visually impaired and challenged persons can read and write using               – Braille system
• A rear-view mirror for driving is     -Convex
• A needle or a pin floats on the surface of water as of             -Surface tension
• The speed of light in air is            –3×108m/s
• Atmospheric pressure decreases with altitude from the           -surface of the Earth
• The process of depositing a layer of a desired metal on another material by means of electricity is called          -Electroplating
• The major hazard of nuclear power generation is         -the storage and disposal of spent or used fuels 
• Hydrogen bomb is based on the principle of      -thermonuclear fusion reaction
• A sound of single frequency is called as -Tone
• What is the audible range of frequency for human beings          –20 Hz – 20 kHz
• Sounds of frequencies below 20 Hz are called   –Infrasonic sound or infrasound
• Sound of frequency above 20kHz is called as    – Ultrasonic sound or ultrasound
• SONAR stands for   – Sound Navigation And Ranging
• An image which can be obtained on a screen is called a          -Real image
• An image which cannot be obtained on a screen is called a        –Virtual image
• A periscope works on the principle of      – Laws of Reflection.
• Distance between the pole and the principal focus of a spherical mirror is called the         -Focal length

• The twinkling of a star is due to    – atmospheric refraction of starlight
• The band of the coloured components of a light beam is called its       – Spectrum
• The kinetic energy of an object increases with its         – Speed
• The atomic number of an element is the number of  Protons in the nucleus of each atom of that element.
• A spring balance is a device commonly used for measuring the _____acting on an object – Force
• The most common isotopes used in a nuclear weapon are     –Uranium and plutonium
• A virtual image larger than the object can be produced by a-   Concave mirror
• What term is used to denote intermixing of particles of two different types of matter on their own?        – Diffusion
• Liquids and gases exert pressure -on the walls of their containers.
• Force per unit area is called         – Pressure.
• The apparent weight of the floating body is        -Zero.
• Relative density                 Density of substance/Density of water
• Law of Energy Conservation        – Energy can neither be created nor be destroyed but transformed from one form to another.
• Which rays are most penetrating?           – Gamma rays
• When light is scattered due to particles in its path, it is called –Tyndall effect.
• The SI unit of luminous intensity is the    -Candela
• The objects that produce their own light are called       – Luminous objects. 
• The splitting of white light into seven colours on passing through a transparent medium is called   –Dispersion of light.
• The tendency of an object to resist the change in the state of its motion is called           -Inertia
• The force acting on an object perpendicular to the surface is called       –Thrust.
• SI unit of mass is     – Kilogram (kg).
• Recoil of gun and motion of rocket are example of       –Newton’s third law of motion
• 1 Horse power         – 746 W
• Motion of an object is presented in pictorial form by their           –Distance-Time graphs.
• Which glass is used in bullet proof screens?                –Reinforced glass