# 100+ Most Important Physics GK DHS Exam Questions And Answers

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100+ Most Important Physics Gk Questions And Answers

Questions for Assam Competitive Examination, ইতিহাসৰ প্ৰশ্ন, Assam Art & Culture Questions, Assam History Question, Assam Geography Question, Questions for Assam Police Examination, PNRD Examination Questions, General Polity Handloom and Textile Examination Questions, DHS Assam, Agriculture Department Examination Questions, Questions for Grade IV Examination, Questions for Junior Assistant Examination, Questions for Grade III Examination, Assam Police, Questions for Sericulture Examination, Questions for SSC GD Preparation, SSC GD old Question paper, SSC GD Mock Test. ## Get Ready With 100+ Most Important Physics General Knowledge Questions:

Q1) Which alloy is used to make clock pendulums:

• A) Mischmetal
• B) Invar
• C) Brass
• D) None of the Above

Ans: B) Invar

Q2) When the red light is exposed on a yellow flower, it will appear ________ in color:

• A) Yellow
• B) Orange
• C) Black
• D) Red

Ans: D) Red

Q3) Longitudinal waves can’t travel through:

• A) Solid
• B) Vacuum
• C) Gas
• D) None of These

Ans: B) Vacuum

Q4) Rose appears red in sunlight, but the same Rose appears __________ in green light:

• A) Red
• B) Black
• C) Green
• D) Yellow

Ans: B) Black

Q5) The current flowing in one direction is called _______:

• A) Alternating Current
• B) Induced Current
• C) Direct Current
• D) Ionic Current

Ans: C) Direct Current

Q6) When detergent is added to water, the surface tension will:

• A) Increases
• B) Decreases
• C) No Change
• D) Become Zero

Ans: B) Decreases

Q7) What is the correct formula for Angular Momentum:

• A) L= r×p
• B) L= r.p
• C) L= p×r
• D) L= p.r

Ans: A) L= r×p

Q8) What is the unit of measurement for the universal gravitational constant:

• A) Nm/Kg²
• B) Nm²/Kg
• C) Nm²/Kg²
• D) Nm²Kg²

Ans: C) Nm²/Kg²

Q9) Rockets work on the principle of:

• A) Newton’s First Law
• B) Newton’s Second Law
• C) Newton’s Third Law
• D) Archimedes Principle

Ans: C) Newton’s Third Law

Q10) Tesla is a unit of magnetic ________:

• A) Flux
• B) Induction
• C) Moment
• D) Field

Ans: B) Induction

Q11) Doppler’s effect is associated with:

• A) Electric Current
• B) Light
• C) Heat
• D) Sound

Ans: D) Sound

Q12) What is the unit of noise pollution:

• A) Decibel
• B) Decimal
• C) ppm
• D) Hertz

Ans: A) Decibel

Q13) Temperatures in centigrade and Fahrenheit are the same at:

• A) 32°
• B) 40°
• C) -40°
• D) -273°

Ans: C) -40°

Q14) Butter paper is an example of a ______ object:

• A) Transparent
• B) Translucent
• C) Opaque
• D) Luminous

Ans: B) Translucent

Q15) Which of the following is not a part of the AC generator:

• A) Slip Rings
• B) Coil
• C) Commutator
• D) Galvanometer

Ans: C) Commutator

Q16) What is the measuring unit for the length of light waves:

• A) Barrel
• B) Angstrom
• C) Knot
• D) Carat

Ans: B) Angstrom

Q17) A magnifying glass comprises a simple:

• A) Convex Lens
• B) Convex Mirror
• C) Concave Lens
• D) None of These

Ans: A) Convex Lens

Q18) The intensity ratio of waves is 25:9. What is the ratio of their amplitudes:

• A) 5:3
• B) 3:5
• C) 25:9
• D) 50:18

Ans: A) 5:3

Q19) Plank constant has the dimensions of:

• A) Energy
• B) Linear Momentum
• C) Angular Momentum
• D) Force

Ans: A) Energy

Q20) 1 CLS unit is equals to:

• A) 1.2 Times the Mass of the Sun
• B) 1.3 Times the Mass of the Sun
• C) 1.4 Times the Mass of the Sun
• D) 1.6 Times the Mass of the Sun

Ans: C) 1.4 Times the Mass of the Sun

Q21) What is the complete form of RADAR:

• A) Radio Detecting and Ranging
• B) Radio Device and Ranging
• C) Radio Detects and Range
• D) Region Device and Ranging

Ans: A) Radio Detecting and Ranging

Q22) The rate of change in displacement over time is called _______:

• A) Acceleration
• B) Speed
• C) Velocity
• D) None of These
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Ans: C) Velocity

Q23) The _______ lens is thick at the middle and thin at the edges:

• A) Concave
• B) Convex
• C) Bifocal
• D) None of These

Ans: B) Convex

Q24) Which of the following metals has the greatest thermal and electrical conductivity:

• A) Silver
• B) Copper
• C) Iron
• D) None of These

Ans: A) Silver

Q25) The Tyndall effect is due to:

• A) Scattering of Light
• B) Dispersion of Light
• C) Refraction of Light
• D) Reflection of Light

Ans: A) Scattering of Light

Q26) Fulminology is the study of:

• A) Volcanic Eruptions
• B) Lightening
• C) Natural Gases
• D) Atmosphere

Ans: B) Lightening

Q27) Which of the following statements is always true:

• A) Displacement > Distance
• B) Displacement < Distance
• C) Displacement = Distance
• D) None of These

Ans: B) Displacement < Distance

Q28) The whistle of a fast-moving rail engine is heard ascending-descending when it crosses the station; it is called:

• A) Peltier Effect
• B) Doppler Effect
• C) Ultrasonic Voice
• D) Subsonic Effect

Ans: B) Doppler Effect

Q29) The velocity of sound doesn’t affect:

• A) Heat
• B) Medium
• C) Pressure
• D) Humidity

Ans: C) Pressure

Q30) Curie is a unit of:

• A) Current
• B) Voltage
• C) Luminous Intensity

Q31) A diode is used for:

• A) Modulation
• B) Oscillation
• C) Amplification
• D) Rectification

Ans: D) Rectification

Q32) The scientist associated with flotation is:

• A) Archimedes
• B) Newton
• C) Louis Pasteur
• D) None of These

Ans: A) Archimedes

Q33) The unit of Viscosity is:

• A) Poise
• B) Pascal
• C) Poiseuille
• D) None of These

Ans: C) Poiseuille

Q34) Acceleration is inversely proportional to:

• A) Force
• B) Velocity
• C) Mass
• D) Distance

Ans: C) Mass

Q35) Which among the following waves can’t be polarized:

• A) Sound
• C) Infrared
• D) Ultraviolet

Ans: A) Sound

Q36) What is the frequency of direct current:

• A) 50 Hz
• B) 60 Hz
• C) Zero
• D) Infinite

Ans: C) Zero

Q37) The value of acceleration due to gravity at the equator will _______ when the earth stops rotating:

• A) Increase
• B) Decrease
• C) Become Zero
• D) Remains Same

Ans: A) Increase

Q38) Which of the following is used in the oven:

• A) X-Rays
• B) UV Rays
• C) Microwaves

Ans: C) Microwaves

Q39) Who enunciated the laws of planetary motion:

• A) Nicolaus Copernicus
• B) Johannes Kepler
• C) Issac Newton
• D) Galileo

Ans: B) Johannes Kepler

Q40) Which of the following diodes is most commonly used as a voltage regulator:

• A) LED
• B) Zener Diode
• C) Var actor Diode
• D) Tunnel Diode

Ans: B) Zener Diode

Q41) Gamma rays can cause:

• A) Gene Mutation
• B) Sneezing
• C) Burning
• D) Fever

Ans: A) Gene Mutation

Q42) Hydraulic machines work on the principle of:

• A) Newton’s Law
• B) Joule’s Law
• C) Pascal’s Law
• D) Flotation Law

Ans: C) Pascal’s Law

Q43) Name the commercial unit of electric energy:

• A) Kwh
• B) Ampere
• C) Volt
• D) Ohm

Ans: A) Kwh

Q44) One calorie is equal to:

• A) 1.284J
• B) 4.186J
• C) 6.418J
• D) 8.146J

Ans: B) 4.186J

Q45) What is the refractive index of a diamond:

• A) 1.44
• B) 1.47
• C) 1.77
• D) 2.42

Ans: D) 2.42

Q46) The upward force on a floating body is called ______:

• A) Jerk
• B) Buoyancy
• C) Archimedal Force
• D) Anti Gravity

Ans: B) Buoyancy

Q47) Which colour is formed when Yellow and Cyan are mixed:

• A) Red
• B) Green
• C) Blue
• D) White

Ans: B) Green

Q48) _____ are used in RADAR systems:

• A) Ultraviolet
• B) Infrared
• D) All of These

Q49) 10⁴ Fermi is equal to:

• A) 1 Meter
• B) 100 Micron
• C) 1 Angstrom
• D) 0.1 Angstrom
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Ans: C) 1 Angstrom

Q50) Rad/sec is the unit of:

• A) Angular Displacement
• B) Angular Velocity
• C) Angular Acceleration
• D) None of These

Ans: B) Angular Velocity

Q51) 1 Micron is equal to:

• A) 100 mm
• B) 1000 mm
• C) 0.01 mm
• D) 0.001 mm

Ans: C) 0.01 mm

Q52) Which of the following is an auxiliary unit:

• C) Ampere
• D) Both A and B

Ans: D) Both A and B

Q53) _____ is used to examine the internal parts of our body:

• A) Microscope
• B) Periscope
• C) Odometer
• D) Endoscope

Ans: D) Endoscope

Q54) Which instrument is used to measure the height or elevation:

• A) Micrometre
• B) Telemeter
• C) Hypsometer
• D) Tonometer

Ans: C) Hypsometer

Q55) To measure the strength of direct current _____ is used:

• A) Tachometer
• B) Spectrometer
• C) Voltmeter
• D) Tangent Galvanometer

Ans: D) Tangent Galvanometer

Q56) Find out the true statements regarding thermal conductivity:

• A) Steel>Wood>Water
• B) Steel>Water>Plastic
• C) Water>Wood>Steel
• D) Water>Steel>Plastic

Ans: B) Steel>Water>Plastic

Q57) As the temperature increases, the thermal conductivity of the solid metal ______:

• A) Increases
• B) Decreases
• C) Remains Same
• D) None of These

Ans: B) Decreases

Q58) _____ is the external energy applied on a body to change its state of rest or uniform motion:

• A) Force
• B) Pressure
• C) Buoyancy
• D) Impulse

Ans: A) Force

Q59) If a car is running at a speed of 72 km/hr and stops after 45 seconds, then what will be the retardation:

• A) 0.3 m/s²
• B) 0.25 m/s²
• C) 0.44 m/s²
• D) 3 m/s²

Ans: C) 0.44 m/s²

Q60) Surface tension depends on:

• A) Atmospheric Pressure
• B) Nature of the Liquid
• C) Temperature of the Liquid
• D) All of These

Ans: D) All of These

Q61) The matric system is also called:

• A) CGS
• B) MKS System
• C) SI
• D) None of These

Ans: B) MKS System

Q62) Plane angle and solid angle are:

• A) Fundamental Quantity
• B) Derived Quantity
• C) Supplementary Quantity
• D) None oy These

Ans: C) Supplementary Quantity

Q63) Which one of the following is not a secondary pigment:

• A) Green
• B) Red
• C) Blue
• D) Yellow

Ans: D) Yellow

Q64) When you look at a mirror, the image you see in the mirror is a __________ image:

• A) Virtual
• B) Real
• C) Reflected
• D) Plain

Ans: A) Virtual

Q65) What type of spectrum is the rainbow:

• A) Natural Spectrum
• B) Artificial Spectrum
• C) Both A and B
• D) None of These

Ans: A) Natural Spectrum

Q66) Which of the following has no units:

• A) Thermal Capacity
• B) Magnetic Susceptibility
• C) Angular Acceleration
• D) None of These

Ans: B) Magnetic Susceptibility

Q67) The primary cause of motion is:

• A) Velocity
• B) Acceleration
• C) Force
• D) Energy

Ans: C) Force

Q68) Gravitational mass is a _______ quantity:

• A) Vector
• B) Scalar
• C) Tensor quantity
• D) None of the above

Ans: A) Vector

Q69) The momentum of a body depends:

• A) Only on its Velocity
• B) Only on its Mass
• C) Both A and B
• D) None of the Above

Ans: C) Both A and B

Q70) The force acting on a body is always parallel to:

• A) Velocity
• B) Acceleration
• C) Momentum
• D) None of the Above

Ans: B) Acceleration

Q71) A body whose momentum is a constant must have a constant:

• A) Acceleration
• B) Force
• C) Velocity
• D) None of These

Ans: C) Velocity

Q72) The motion of a bicycle wheel is:

• A) Translatory
• B) Rotary
• C) Both A and B
• D) Curvilinear

Ans: C) Both A and B

Q73) Force × time = _________:

• A) Momentum
• B) Impulse
• C) Force
• D) None of These

Ans: B) Impulse

Q74) Inertia is proportional to:

• A) Mass
• B) Weight
• C) Length
• D) Height

Ans: A) Mass

Q75) The dimensional formula of the Planck’s constant is:

• A) [ML2T-2]
• B) [MLT]
• C) [M2L2T3]
• D) [ML2T-1]

Ans: D) [ML2T-1]

Q76) Light cannot be polarized by:

• A) Reflection
• B) Diffraction
• C) Refraction
• D) All of These

Ans: B) Diffraction

Q77) Total internal reflection would takes place if:
light passes:

• A) From Air to Water
• B) From Water to Glass
• C) From Glass to Diamond
• D) From Glass to Water

Ans: D) From Glass to Water

Q78) If the length of a pendulum is doubled and the diameter of its ball is reduced to half, it’s time period will be:

• A) √2
• B) Half
• C) Remains Same
• D) Double

Ans: A) √2

Q79) A particle is thrown upwards at a speed of 39.2 m/s. Calculate it’s time for maximum height:

• A) 3 Sec
• B) 4 Sec
• C) 5 Sec
• D) 6 Sec

Ans: B) 4 Sec

Q80) Electric wires are generally coated with:

• A) Polypropylene
• B) Polyvinyl Chloride
• C) Polyurethane
• D) Polyethylene

Ans: B) Polyvinyl Chloride

Q81) The presence of free ___________ in a substance makes it a conductor of electricity:

• A) Positrons
• B) Protons
• C) Electrons
• D) Neutrons

Ans: C) Electrons

Q82) During fog we cannot see because of:

• A) Reflection
• B) Internal Reflection
• C) Refraction
• D) Scattered Light

Ans: D) Scattered Light

Q83) ___________ determines the speed of sound in a medium:

• A) Tone of the Wave
• B) Time of the Wave
• C) Properties of the Medium
• D) Amplitude of the Wave

Ans: C) Properties of the Medium

Q84) When the angle between the force and the displacement is 90, the work done is __________:

• A) Neutral
• B) Negative
• C) Zero
• D) Positive

Ans: C) Zero

Q85) ________ is the change in velocity per unit time:

• A) Acceleration
• B) Momentum
• C) Force
• D) Inertia

Ans: A) Acceleration

Q86) When speed of an object exceeds the velocity of sound, then it is said to be moving with ______ speed:

• A) Subsonic Speed
• B) Supersonic Speed
• C) Ultrasonic Speed
• D) None of These

Ans: B) Supersonic Speed

Q87) Ultrasound is used to detect ________ in metal blocks:

• A) Metal heat
• B) Cracks and Flaws
• C) Metal Opacity
• D) Metal Heaviness

Ans: B) Cracks and Flaws

Q88) Water exists as _______ in its solid state:

• A) Ice
• B) Clouds
• C) Foam
• D) Steam

Ans: A) Ice

Q89) 18 Volts= ________ × 3 Ohms:

• A) 6 Amperes
• B) 6 Watts
• C) 6 Milliamperes
• D) 6 Joules

Ans: A) 6 Amperes

Q90) Solar energy __________ generates more power than wind energy:

• A) Sometimes
• B) Always
• C) Never
• D) Often

Ans: A) Sometimes

Q91) Plasma is formed in stars due to _________:

• A) High Temperature
• B) High Pressure
• C) Low Temperature
• D) None of These

Ans: A) High Temperature

Q92) _________ waves include visible light waves, X-rays, gama rays, radio waves, microwaves, ultraviolet and infrared waves:

• A) Mechanical
• B) Magnetic
• C) Electromagnetic
• D) Electric

Ans: C) Electromagnetic

Q93) Which of the following is not a characteristic of sound waves:

• A) Velocity
• B) Nature
• C) Wavelength
• D) None of These

Ans: B) Nature

Q94) Echocardiogram is used in __________:

• A) Bioelectricity
• C) X-rays
• D) None of These

Q95) Which of the following lamp has the highest energy efficiency:

• A) LED
• B) CFL
• C) Arc Lamp
• D) None of These

Ans: A) LED

Q96) The minimum speed required by a spacecraft to escape the gravitational pull is ________:

• A) 6 Miles/sec
• B) 7 Km/sec
• C) 7 Miles/sec
• D) 10 Miles/sec

Ans: C) 7 Miles/sec

Q98) Acceleration due to gravity (g)= ___________:

• A) G/MR²
• B) GR²/M
• C) GM/R²
• D) GM/R

Ans: C) GM/R²

Q99) Mechanical energy is equal to:

• A) Kinetic + Chemical Energy
• B) Kinetic + Potential Energy
• C) Kinetic + Heat Energy
• D) Kinetic + Electrical Energy

Ans: B) Kinetic + Potential Energy

Q100) If a plane travels a distance of 4000 M with the work done of 2000 J, then the force applied is:

• A) 5 N
• B) 10 N
• C) 25 N
• D) 50 N

Ans: A) 5 N