Physics Class 3

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 1. Mirage is due to _________

1. Equal heating of different parts of the atmosphere
2. Magnetic disturbances in the atmosphere
3. Depletion of ozone layer in the atmosphere
4. Unequal heating of different parts of the atmosphere

Answer: D

2. Light year is a unit of ___________

1. Time
2. Light
3. Intensity of light
4. distance

Answer: D

3. The light from the sun reaches us in nearly__________

1. 8 minutes
2. 4 minutes
3. 2 minutes
4. 16 minutes

Answer: A

4. ___________is not used in the field of physics.

1. Stock value
2. Latent heat
3. Nuclear fusion
4. Refractive index

Answer: A

5. The working principle of a washing machine is ____________

1. diffusion
2. centrifugation
3. reverse osmosis
4. dialysis

Answer: B

6. The speed of light will be minimum while passing through_________

1. water
2. air
3. vaccum
4. glass

Answer: D

7. The stars appears to move from east to west because___________

1. The earth rotates from east to west
2. The earth rotates from west to east
3. All stars move from east to west
4. The background of the stars moves from west to east

Answer: B

8. Radiocarbon is produced in the atmosphere as result of ____________

1. Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
2. collision between fast neutrons and nitrogen nuclei present in the atmosphere.
3. Action of ultraviolet light from the sun on atmospheric oxygen
4. Lightning discharge in atmosphere

Answer: B

9. Nuclear sizes are expressed in a unit named____________

1. Tesla
2. Newton
3. Angstrom
4. Fermi

Answer: D

10. Planets do not twinkle because_________

1. They are nearer to earth and hence we receive a greater amount of light
2. They are very far away from the earth resulting in decrease in intensity of light
3. They emit light of a constant intensity
4. Their distance from the earth does not change with time

Answer: A

11. The absorption of ink by blotting paper involves ___________

1. Siphon action
2. Diffusion of ink through the blotting
3. capillary action phenomenon
4. Viscosity of ink

Answer: C

12. RADAR is used for_____________

1. receiving a signals in a radio receiver
2. locating submerged submarines
3. locating geostationary satellites
4. detecting and locating the position of objects such as Aeroplanes

Answer: D

13. Sound waves in air are_____________

1. electromagnetic
2. longitudinal
3. polarized
4. transverse

Answer: B

14. Sound of frequency below 20 Hz is called___________

1. audio sounds
2. infrasonic
3. supersonics
4. ultrasonic

Answer: B

15. Select the Scalar Quantity_________

1. Pressure
2. Force
3. Velocity
4. Acceleration

Answer: A

16. Metals are good conductors of electricity because________

1. They have high melting point
2. The atoms are lightly packed.
3. They contain free electrons
4. All of the above

Answer: C

17. Moment of inertia is____________

1. Phasor
2. Scalar
3. Vector
4. Tensor

Answer: D

18. Sound travels at the fastest speed in__________

1. water
2. steel
3. air
4. vacuum

Answer: B

19. One thousand microns is equal to___________

1. 10-3m
2. 10-9m
3. 10-6m
4. 10-12m

Answer: A

20. Superconductors are substances which ________

1. offer no resistance to the flow of electricity
2. offer high resistance to the flow of current
3. conduct electricity at high temperatures
4. conduct electricity at low temperature

Answer: A

21. Radio telescopes are better than optical telescopes because

1. they can detect faint galaxies which no optical telescope can
2. they can work even in cloudy conditions
3. they can work during the day and night
4. All of the above

Answer: D

22. Intensity of sound at a point is  its distance from the source

1. directly proportional to square of
2. directly proportional to square of
3. inversely proportional to square of
4. inversely proportional to

Answer: C

23. Rainbow is due to _____

1. refraction and reflection of sunlight by water droplets
2. absorption of sunlight in minute water droplets
3. diffusion of sunlight through water droplets
4. ionization of water deposit

Answer: A

24. Isotopes of an elements contain _______

1. equal number of protons and electrons
2. the same number of protons but different number of neutrons
3. the same number of neutrons but different number of protons
4. equal number of nucleons

Answer: B

25. The purpose of choke in tube light is________

1. Induce low resistance
2. Induce high voltage
3. Induce low voltage
4. Induce high resistance

Answer: B

26. Sir C.V. Raman was awarded Nobel prize for his work connected with which of the following phenomenon of radiation?

1. Diffraction
2. Interference
3. Scattering
4. Polarization

Answer: C

27. Supersonic plane fly with the speed________

1. of sound
2. less than the speed of sound
3. greater than the speed of sound
4. of light

Answer: C

28. The optical fibre works on the _______

1. total internal reflection
2. principle of refraction
3. interference
4. scattering

Answer: A

29. Mercury is commonly used as a thermometric fluid rather than water because__________

1. density of mercury is more than the water
2. specific heat of mercury is less than water
3. specific heat of mercury is more than water
4. mercury has greater visibility than water

Answer: D

30. Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit _________

1. X-rays
2. ultraviolet light
3. radio waves
4. visible light

Answer: D

Q.31 Which of the following measurements is not a unit of distance?  

(A) Ammeter
(B) Cubit
(C) Parsec
(D) angstrom

Ans. A

Q.32 Which one of the following remains constant while throwing a ball upward?  

(A) Displacement
(B) Kinetic energy
(C)  Acceleration
(D)   Velocity

Ans. C

Q.33 Pure water freezes at what temperature?  

(A) 47 F
(B) 32 F
(C)  0 F
(D)   19 F

Ans. B

Q.34 Which vitamin is abundant in citrus fruits?  

(A) Vitamin A
(B) Vitamin B
(C)  Vitamin C
(D)   Vitamin D

Ans. C

Q.35 Zinc Oxide is  

(A) Acidic
(B) Basic
(C)  Neutral
(D)   Amphoteric

Ans. D

Q.36 Pure water is a _____________ Conductor of electricity.  

(A) super conductor
(B) bad conductor
(C)  speed conductor
(D)   None of these

Ans. B

Q.37 What element’s three isotopes have different names?  

A. Helium
B. Oxygen
C. Carbon
D. Hydrogen

Ans. D

Q.38 On which one of the following conservation laws, does a rocket work?  

(A) Mass
(B) Energy
(C)  Linear momentum
(D)   Angular momentum

Ans. C

Q.39 Which one among the following radiations carries maximum energy?  

(A) Ultraviolet rays
(B) Gamma rays
(C)  X- rays
(D)   Infra red rays

Ans. B

Q.40 The Central Arid Zone Research Institute (CAZRI) is located at  

(A) Jaipur
(B) Jodhpur
(C)  Jaisalmer
(D)   Jallandhar

Ans. B

Q.41 What is the main constituent of coal gas?  

(A) Oxygen
(B) Water
(C)  Nitrogen
(D)   Methane

Ans. C

Q.42 Recoil of a gun is an example of  

(A) Conservation of mass
(B) conservation of energy
(C)  conservation into KE
(D)   conservation of linear momentum

Ans. D

Q.43 What is the heaviest of the naturally occurring Noble gases?  

(A) Radon
(B) Xenon
(C) Helium
(D) Argon

Ans. A

Q.44 Aviation fuel for Jet aero planes consists of purified  

(A) Petrol
(B) Kerosene
(C) Gasoline
(D) Diesel

Ans. B

Q.45 A piece of stone and or iron traveling through space that moves through the earth’s atmosphere is  

(A) Planet
(B) Sun
(C) Moon
(D) Meteor

Ans. D

Q.46 Which one of the following common devices works on the basis of the principle of mutual induction?  

(A) Tube light
(B) Transformer
(C) Photodiode
(D) Led

Ans. B

Q.47 Dc current can be controlled by which one of the following components?  

(A) Impedance
(B) Resistance
(C) Capacitance
(D) Inductance

Ans. B

Q.48 Mesons are found in  

(A) Alpha -rays
(B) Laser beam
(C) X – rays
(D) Cosmic rays

Ans. D

Q.49 A moderator is used in nuclear reactors in order to  

(A) increase the motoneurons
(B) decrease the motoneurons
(C) slow down the speed of neutrons
(D) Anthony S. D’Mello

Ans. C

Q.50 The wavelength of X-rays is of the order of  

(A) 1 cm
(B) 1 m
(C) 10 micron
(D) 1 Angstrom

Ans. D

Q.51 In a sitar wire which one of the following types of vibration is produced?  

(A) Progressive longitudinal
(B) Stationary longitudinal
(C) Progressive transverse
(D) Stationary transverse

Ans. A

Q.52 Which gas in the atmosphere saves us from the ultra violet rays of the sun?  

(A) Nitrogen
(B) Oxygen
(C) Ozone
(D) Carbon Monoxide

Ans. C

Q.53 What is the study of plants called?  

(A) Physics
(B) Chemistry
(C) Zoology
(D) Biology

Ans. D

Q.54 The three methods of science are observation, experimentation and  

(A) Hypothesis
(B) Measurement
(C) Deduction
(D) inference

Ans. B

Q.55 If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then both bodies acquire the same.

(A) velocity

(B) kinetic energy

(C) acceleration

(D) momentum

Ans. D

Q.56 Pick out the scalar quantity

(A) force

(B) pressure

(C) velocity

(D) acceleration

Ans. B

Q.57 Rectifiers are used to convert

(A) Direct current to alternating current

(B) alternating current to direct current

(C) high voltage to low voltage

(D) low voltage to high voltage

Ans. B

Q.58  _____Of the following properties of a wave, the one that is independent of the other is its.

(A) amplitude

(B) velocity

(C) wavelength

(D) frequency

Ans. A

Q.59 Find the maximum velocity for the overturn of a car moving on a circular track of radius 100m. The co-efficient of friction between the road and tyre is 0.2.

(A) 0.14 m/s

(B) 140 m/s

(C) 1.4 m/s

(D) 14 m/s

Ans. D

Q.60 It is more difficult to walk on a sandy road than on a concrete road because

(A) sand is soft and concrete is hard

(B) the friction between sand and feet is less than that between concrete and feet

(C) the friction between sand and feet is more than that between concrete and feet

(D) the sand is grainy but concrete is smooth

Ans. B

Q.61 Magnetism at the centre of a bar magnet is

(A) minimum

(B) maximum

(C) zero

(D) minimum of maximum

Ans. C

Q.62 Out of the following which is not emitted by radioactive substance?

(A) Electrons

(B) Electromagnetic radiations

(C) Alpha particles

(D) Neutrons

Ans. D

Q.63 Lux is the SI unit of

(A) intensity of illumination

(B) luminous efficiency

(C) luminous flux

(D) luminous intensity

Ans. A

Q.64 On a rainy day, small oil films on water show brilliant colours. This is due to

(A) dispersion

(B) interference

(C) diffraction

(D) polarization

Ans. B

Q.65 Point A is at a lower electrical potential than point B. An electron between them on the line joining them will.

(A) move towards A

(B) move towards B

(C) move at right angices to the line joining A and B

(D) remain at rest

Ans. B

Q. 66 Material for rain-proof coats and tents owe their water-proof properties to

(A) surface tension

(B) viscosity

(C) specific gravity

(D) elasticity

Ans. A

Q.67 RADAR is used for

(A) locating submerged submarines

(B) receiving a signal in a radio receiver

(C) locating geostationary satellites

(D) detecting and locating the position of objects such as airplanes

Ans. D

Q.68 Sound of frequency below 20 Hz is called.

(A) audio sounds

(B) infrasonic

(C) ultrasonic

(D) supersonics

Ans. B

General Knowledge Questions about Physics

Q1: Who gave the theory of Relativity?
Ans: Albert Einstein.

Q2: Rectifier is a device convert  current  in which manner?
Ans: A.C to D.C

Q3: What is the SI unit of mass?
Ans: Kg

Q4: What is charge inside any closed surface?
Ans: zero

Q5: Which device use to regulate voltage?
Ans: Zener Diode

Q6: Which instrument is used to  measures the relative humidity of atmosphere?
Ans: Hygrometer

Q7: The blue color of sky is due to?
Ans: scattering of light

Q8: The unit of temperature in SI method?
Ans: Kelvin

Q9: What does not change in medium speed, wavelength, frequency?
Ans: frequency

Q10: What type of  wave propagation use to get signal  from Satellite?
Ans: space wave

Q11: Which instrument measure the specific gravity?
Ans: Hydrometer

Q12: Instrument is used to see small object?
Ans: Microscope

Q13 : Gravitational force is maximum at ?
Ans: poles.

Q14: which force is greater gravitational or electrostatic?
Ans: electrostatic.

Q15: What type of  energy used to move a object?
Ans: kinetic energy

Q16: Is acceleration is a vector quantity?
Ans: Yes.

Q17: What is dimension of strain?
Ans: Strain is dimensionless .

Q18: What is the SI unit of magnetic flux?
Ans: Weber

Q19: Which among the following temperature scale is based upon absolute zero?
Ans: Kelvin

Q20: Which of the following scientific discoveries was made by C.V Raman?
Ans: Inelastic scattering of light by molecules

Q21: Which of the following units is the smallest in terms of length?
Ans: fermi

Q22: Which of the following is true about the effect of altitude on the value of acceleration due to gravity?
Ans: The acceleration due to gravity decreases with height

Q23: What is the time period for a satellite orbiting close to the surface of earth?
Ans: 84.6 minutes

Q24: Which of these represent the Angular momentum of a satellite?
Ans: mvr

Q25: What is the order of distance for Vander Wall forces to be active?
Ans: 10–9 metre

Q26: What is the unit of Specific gravity?
Ans: No units

Q27: The absorption of ink by blotting paper involves
Ans: capillary action phenomenon

Q28: Nuclear sizes are expressed in a unit named
Ans: Fermi

Q29: Light year is a unit of
Ans: distance

Q30: What device is used by law enforcement agencies in lie detection test?
Ans: Polygraph

Q31: What is the orbital speed of satellite near the earth?
Ans: v 2 = gr

Q32: Newton third law of motion apply on ?
Ans: two different bodies.

Q33: Candela is the SI unit of ?
Ans: Luminous intensity

Q34: Mirage is due to
Ans: unequal heating of different parts of the atmosphere

Q35: Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit
Ans: visible light

Q36: Mercury is commonly used as a thermometric fluid rather than water because
Ans: mercury has greater visibility than water

Q37: Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in
Ans: 4.2 years

Q38: Scalars are quantities that are described by _____________
Ans: Magnitude

Q39: Vectors are the quantities that are described by _______________
Ans: magnitude & direction

Q40: What is the metric unit of force?
Ans: Newton

Q41: If electrical conductivity increases with the increase of temperature of a substance, then it is a:
Ans: Semiconductor

Q42: A piece of ice is dropped in a vesel containing kerosene. When ice melts, the level of kerosene will
Ans: Fall

Q43: A man presses more weight on earth at :
Ans: Standing Position

Q44: Stars which appear single to the naked eye but are double when seen through a telescope are
Ans: binariesC

Q45: Which one of the following is the unit of activity of a radioactive source?
Ans: Becquerrel

Q46: Which one among the following radiations carries maximum energy?
Ans: gamma rays

Q47: Who suggested that light is made up of packets of energy known as protons?
Ans: Albert Einstein

Q48: Which Austrian physicist developed the philosophy that all knowledge is simply sensation?
Ans: Ernest Mach

Q49: Who in 1939 suggested the name meson for middle-weight particles?
Ans: Homi J. Bhabha

Q50: Who in 1643 was the first person to create vacuum above the liquid?
Ans: Evangelista Torricelli

Q51: Write an example of second order of levers?
Ans: Lime squeezer

Frequently asked Physics Questions and Answers for Competitive Exams

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