## general science

### Physics MCQ Questions and Answers Page - 2

1.
 A micron is equal to A 0.1 mm B 0.01 mm C 0.001 mm D 0.0001 mm Answer : C Explanation :
2.
 Amount of water vapour (gaseous) in a given volume of air (cable metre) is known as : A Mixing ratio B Relative humidity C Absolute humidity D Specific humidity Answer : C Explanation :
3.
 When a running car stops suddenly, the passengers tends to lean forward because of : A Centrifugal force B Inertia of rest C Inertia of motion D Gravitational force Answer : C Explanation :
4.
 When a strong beam of light is passed through a colloidal solution, the light will A Be scattered B Pass unchanged C Be absorbed D Be reflected Answer : A Explanation :
5.
 When a body fails from an aeroplane, there is increase in its A Kinetic energy B Mass C Acceleration D Potential energy Answer : C Explanation :
6.
 The motion of a body that repeats itself after a regular interval of time is A a periodic motion B a simple harmonic motion C an aperiodic motion D an oscillatory motion Answer : A Explanation :
7.
 Specific gravity is defined as the ratio of A Density of the substance to the density of water B Density of the substance to the density of water at 00C C Density of water at 40C to the Density of the substance D Density of the substance to the Density of water at 40C Answer : A Explanation :
8.
 One bar is equal to A 103 Pa B 100 Pa C 105 Pa D 104 Pa Answer : C Explanation :
9.
 A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity. The rubber ball rebounds and the metal ball does not rebound. It can be concluded that A The rubber ball suffers greater change in momentum B The metal ball suffers greater change in momentum C Both suffer the same change in momentum D The initial momentum of the rubber ball is greater than that of the metal ball Answer : A Explanation :
10.
 Kepler’s law of planetary motion states that the square of the time period is proportional to the A Semi-major-axis B Square of the Semi-major-axis C Cube of the Semi-major-axis D Fourth power of the Semi-major-axis Answer : C Explanation :
11.
 The dimension MLT-2 corresponds to A Force B Work done C Acceleration D Velocity Answer : A Explanation :
12.
 The density of water bis 1 g/cc. This is strictly valid at A 00 C B 40 C C 250 C D 1000 C Answer : B Explanation :
13.
 The speed of light in air is A 3 × 108  m/s B 3 × 10-8   m/s C 8 × 103  m/s D Infinity Answer : A Explanation :
14.
 A man standing on a edge of a cliff throws a stone vertically upwards with a certain speed. He then throws another stone downwards with the the same speed. Find the ratio of the speeds of the two s A 1 : 1 B 1 : 2 C 1 : 4 D Cannot be found from the given information. Answer : A Explanation :
15.
 The mass of a body measured by a physical balance in a lift at rest is found to be m. If the lift is going up with an acceleration a, its mass will be measured as A
16.
 The dimensional formula for universal gravitational constant is A M-1 L3 T2 B M L2 T-2 C M-2 D M-1 L3 T-2 Answer : D Explanation :
17.
 Rocket works on the principle of A Newton’s third Law B Newton’s First Law C Newton’s second Law D Archimedes principle Answer : A Explanation :
18.
 The weight of a body acts through the centre of A Gravity B Both C Both (a) and (b) D Buoyancy Answer : A Explanation :
19.
 A wheel-barrow is an example of A Class III lever B Pully system C Class I lever D Class II lever Answer : D Explanation :
20.
 The motion of a body around a circular path is an example of A Uniform velocity, variable acceleration B Uniform speed, Uniform velocity C Uniform speed, variable velocity D Uniform speed, variable acceleration Answer : A Explanation :
21.
 Flywheel is an important part of a steam engine because it : A Accelerates the speed of the engine B Helps the engine in keeping the speed Uniform C Decreases the moment of inertia D Gives strength to the engine Answer : B Explanation :
22.
 Relative humidity is expressed as A Grams B Kilograms C Percentage D Ratio Answer : C Explanation :
23.
 The motion of the wheels of a bullock-cart while moving on the road is an example of A Oscillatory and rotatory motion B Oscillatory and translator  motion C Translator and rotatory motion D Translator motion only Answer : C Explanation :
24.
 If both the mass and the velocity of a body is increased to twice of their magnitude, the kinetic energy will increase by A 2 times B 4 times C 8 times D 16 times Answer : B Explanation :
25.
 Two bodies kept at a certain distance feel a gravitational force F to each other. If the distance between them is made double the former distance, the force will be A 2F B $\frac{1}{2}&space;F$< C 4F D $\frac{1}{4}&space;F$< Answer : D Explanation :
26.
 A system exhibiting S.H.M. must possess A Elasticity as well as inertia B Elasticity, inertia and an external force C Elasticity only D Inertia only Answer : A Explanation :
27.
 The moment of inertia of a body does not depend upon its A Axis of rotation B Angular velocity C Form of mass D Distribution of mass Answer : B Explanation :
28.
 To open a door easily, the handle should be fixed A Near the hinges B Away from mid-point opposite to hinges C In the middle D None of these Answer : D Explanation :
29.
 A particle is moving in a uniform circular motion with constant speed v along a circle of radius r. The acceleration of the particle is A Zero B $\frac{v}{r}$ C $\frac{v}{r^{2}}$ D $\frac{v^{2}}{r}$ Answer : D Explanation :
30.
 Period of oscillation of 3 cm microwaves in seconds is A 1 × 1010 B 1 × 10-10 C 0.01 D 0.001 Answer : B Explanation :
31.
 An object covers distance which is directly proportional to the square of the time. Its acceleration is A Increasing B Decreasing C Zero D Constant Answer : D Explanation :
32.
 If the horizontal range of a projectile is four times its maximum height, the angle of projection is A 300 B 450 C $sin^ D $tan^{ Answer : B Explanation :
33.
 Which of the following have the same unit ? A Work and power B Torque and moment of inertia C Work and torque D Torque and angular momentum Answer : C Explanation :
34.
 In a particular system, the units of length, mass and time are chosen to be 10 cm, 10 g and 0.1 s respectively. the unit of force in this system will be equivalent to A 0.1 N B 1 N C 10 N D 100 N Answer : A Explanation :
35.
 Distances of stars are measured in A Galactic unit B Stellar mile C Cosmic kilometre D Light year Answer : D Explanation :
36.
 A man standing at the top of a tower has two spheres A and B. he drops sphere A downwards and throws sphere B horizontally at the same time. Which of the following is correct ? A Both the spheres will reach the ground simultaneously. B A will reach the ground first. C B will reach the ground first. D The question is incomplete because the masses of the spheres are not given. Answer : A Explanation :
37.
 Water has maximum density at A 1000 C B 00 C C 40 C D 2730 C Answer : C Explanation :
38.
 If a body moves with a constant speed in a circle A No work is done on it B No force acts on it C No acceleration is produced in it D Its velocity remains constant Answer : D Explanation :
39.
 Which of the following is a scalar quantity ? A Velocity B Force C Angular momentum D Electrostatic potential Answer : D Explanation :
40.
 Which of the following is not a vector quantity ? A Speed B Velocity C Torque D Displacement Answer : A Explanation :
41.
 An object with a constant speed A Is not accelerated B Might be accelerated C Is always accelerated D Also has a constant velocity Answer : A Explanation :
42.
 A man in a train moving with a constant velocity drops a ball on the platform. The path of the ball as seen by an observer standing on the platform is A A straight line B A circle C A parabola D Answer : C Explanation :
43.
 A person can jump higher on the moon’s surface than on the earth because : A The moon’s surface is rough B The acceleration due to gravity in moon is smaller than that on the earth C The moon is cooler than earth D The moon has no atmosphere Answer : B Explanation :
44.
 The apparent weight of a man in a lift is less the real weight when : A The lift is going up with an acceleration B The lift is going down with uniform speed C The lift is going up with uniform speed D The lift is going down with an acceleration Answer : D Explanation :
45.
 Which one of the following is a non-dimensional quantity ? A Gas constant B Strain C Co-efficient of viscosity D Planck’s constant Answer : B Explanation :
46.
 When water freezes its density A Decreases B Becomes zero C Remains constant D Increases Answer : A Explanation :
47.
 A bullet of mass ‘m’ and velocity ‘’ is fired into a large block of wood of mass ‘M’. The final velocity of the system is A $\frac{M}{m&space;+&a B $\frac{m}{m&space;+&a C $\frac{m&space;+& D $\frac{m&space;+& Answer : B Explanation :
48.
 The amount of matter in a ball of steel is its : A Weight B Mass C Density D Volume Answer : B Explanation :
49.
 If density of oxygen is 16 times that of hydrogen, what will be their corresponding ratio of velocity of sound ? A 4 : 1 B 2 : 1 C 1 : 16 D 1 : 4 Answer : D Explanation :
50.
 ‘Parsec’ is the unit measurement of A Density of stars B Astronomical distance C Brightness of heavenly bodies D Orbital velocity of giant stars Answer : B Explanation :
51.
 The SI unit of luminous emittance is : A Lux B Candela C Lumen D Lumen second Answer : A Explanation :
52.
 The period of revolution of a certain planet in an orbit of radius R is T. Its period of revolution in an orbit of radius 4R will be : A 8 T B 4 T C $2\sqrt{2}$ T D 2 T Answer : A Explanation :
53.
 The weight of a body at the centre of earth is : A Half the weight at the surface B Zero C Twice the weight at the surface D Infinite Answer : B Explanation :
54.
 Which of the following is an example of simple harmonic motion ? A Earth spinning on its axis B Simple pendulum motion C Ball bouncing on floor D Motion of a celling fan Answer : B Explanation :
55.
 Which of the following is the unit of Astronomical Distance ? A Metre/sec B Sec. C Para/sec. D Parsec Answer : D Explanation :
56.
 The washing machine works on the principle of A Dialysis B Diffusion C Reverse osmosis D Centrifugation Answer : D Explanation :
57.
 00  K is equivalent to A 2730 C B - 2730 C C 00 C D 1000 C Answer : B Explanation :
58.
 The absolute zero is a temperature at which  __________ A Molecular motion in a gas would cease B Water freezes C All gases become liquid D All gases become solid Answer : A Explanation :
59.
 A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of  __________ . A Gravitational force between train and man B Illusion of the man C The centripetal force D Pressure difference due to fast moving air in between Answer : D Explanation :
60.
 The temperature of a liquid is 320 F. What is its temperature in Celsius scale ? A 320 C B 00 C C 1000 C D 2120 C Answer : B Explanation :
61.
 The point where total mass of a body is supposed to be concentrated is known as A Dead centre B Centre of mass C Centre of gravity D Centre of motion Answer : B Explanation :
62.
 If there were no gravity, which of the following will not be there for a fluid ? A Viscosity B Surface Tension C Pressure D Upward Thrust Answer : D Explanation :
63.
 If ice floating on water in a vessel melts, the water level in the vessel  __________ . A Increases B Does not change C First increases before decreasing D Decreases Answer : D Explanation :
64.
 Why is weightlessness experienced while orbiting the earth in A Inertia B Acceleration C Zero gravity D Orbital motion Answer : D Explanation :
65.
 Two vectors are said to be equal if A Only their magnitudes are same B Only their directions are same C Both magnitude and direction are same D Magnitudes are same but directions are opposite Answer : C Explanation :
66.
 Why does a cannon recoil after firing ? A Conservation of energy B Backward thrust of gases produced C Newton’s third law of motion D Newton’s first law of motion Answer : C Explanation :
67.
 A bomb explodes on the moon. You will hear its sound on earth after  ____________ A 20 minutes B 2 hours 20 minutes C 3.7 hours D You cannot hear the sound of explosion Answer : D Explanation :
68.
 During the motion of projectile fired from the earth surface, __________ A Its kinetic energy remains constant B Its momentum remains constant C Vertical component of its velocity remains constant D Horizontal component of its velocity remains constant Answer : D Explanation :
69.
 Absolute Zero is defined as A The temperature at which all molecular motion ceases B At which water boils at 298K C At which liquid Helium boils D At which the volume becomes zero Answer : A Explanation :
70.
 A body moving in a circular path with a constant speed has a A Constant velocity B Constant acceleration C Constant kinetic energy D Constant displacement Answer : C Explanation :
71.
 One nanometre is equal to  __________ metres. A 10 raised to the power (-3) B 10 raised to the power (-6) C 10 raised to the power (-9) D 10 raised to the power (-12) Answer : C Explanation :
72.
 What is the unit of relative density ? A Kg/m B Kg/m2 C Kg/m3 D It has no unit Answer : D Explanation :
73.
 Acceleration is A Inversely proportional to force B Inversely proportional to mass C Directly proportional to mass D Directly proportional to force Answer : A Explanation :
74.
 What is the Earth’s escape velocity ? A 2.8 km/s B 5.6 km/s C 11.2 km/s D 14 km/s Answer : C Explanation :
75.
 An object is in static equilibrium when it is  _________ A At rest B Moving in a circular path C Moving with uniform velocity D Accelerating at high speed Answer : A Explanation :
76.
 When net torque is zero,  _________  will be constant A Force B Angular momentum C Linear momentum D Accelerating Answer : B Explanation :
77.
 Newton’s first law is also known as  _________ . A Law of Friction B Law of Momentum C Law of Inertia D Law of Motion Answer : C Explanation :
78.
 Acceleration due to energy on a planet decreases with  _________ . A Decrease in radius of the planet B Increase in mass of the planet C Decrease in mass of the body D Increase in altitude from surface of the planet Answer : D Explanation :
79.
 Why boiling point of water decreases at high altitudes? A Because of high temperature B Because of low atmospheric pressure C Because of low temperature D Because of high atmospheric pressure Answer : B Explanation : Low atmospheric pressure