Physics questions - Physics questions answers
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Competitive Exam Questions and Answers
No: 1
Q. Radiocarbon is produced in the atmosphere as a result of ?
A. collision between fast neutrons and nitrogen nuclei present in the atmominutes
No: 2
Q. It is easier to roll a stone up a sloping road than to lift it vertical upwards because ?
A. work done in rolling a stone is less than in lifting it
No: 3
Q. The absorption of ink by blotting paper involves ?
A. capillary action phenomenon
No: 4
Q. Siphon will fail to work if ?
A. the level of the liquid in the two vessels are at the same height
No: 5
Q. Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to ?
A. both the heating effect of current and hysteresis loss
No: 6
Q. Nuclear sizes are expressed in a unit named ?
A. fermi
No: 7
Q. An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground a bomb is released from it. The bomb strikes the ground at p ?
A. 3.33 km
No: 8
Q. Light year is a unit of ?
A. distance
No: 9
Q. Mirage is due to ?
A. unequal heating of different parts of the atmosphere
No: 10
Q. Light from the Sun reaches us in nearly ?
A. 8 minutes
No: 11
Q. Stars appears to move from east to west because ?
A. the earth rotates from west to east
No: 12
Q. Pa(Pascal) is the unit for ?
A. pressure
No: 13
Q. Planets do not twinkle because ?
A. they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable
No: 14
Q. Mica is used in electrical appliances such as electric iron because mica is ?
A. a good conductor of heat but a bad conductor of electricity
No: 15
Q. It is easier to roll a barrel full of coal tar than to pull it because ?
A. the rolling friction is much less than the sliding friction
No: 16
Q. Minimum number of unequal vectors which can give zero resultant are ?
A. three
No: 17
Q. Intensity of sound has ?
A. an object existence
No: 18
Q. Rain is falling vertically downwards. To a man running east - wards, the rain will appear to be coming from ?
A. east
No: 19
Q. Metals are good conductors of electricity because ?
A. they contain free electrons
No: 20
Q. Let a thin capillary tube be replaced with another tube of insufficient length then, we find water ?
A. will not rise
No: 21
Q. Out of the following pairs, choose the pair in which the physical quantities do not have identicaldimension ?
A. Impulse and moment of force
No: 22
Q. If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same ?
A. momentum
No: 23
Q. Pick out the scalar quantity ?
A. pressure
No: 24
Q. Rectifiers are used to convert ?
A. Alternating current to Direct current
No: 25
Q. Identify the vector quantity from the following ?
A. Angular momentime
No: 26
Q. Large astronomical telescopes always use as objective ?
A. combinations of lenses
No: 27
Q. One should not connect a number of electrical appliances to the same power socket because ?
A. this can damage the domestic wiring due to overloading
No: 28
Q. Rainbow is produced when sunlight fall on drops of rain. Which of the following physical phenomena are responsible for this ?
A. Refraction, Internal reflection
No: 29
Q. Natural radioactivity was discovered by ?
A. Henri Becquerel
No: 30
Q. Planets are ?
A. non - luminous heavenly bodies
No: 31
Q. Out of the following, which is not emitted by radioactive substance?
A. Neutrons
No: 32
Q. Sound waves in air are ?
A. longitudinal
No: 33
Q. Magnetism at the centre of a bar magnet is ?
A. zero
No: 34
Q. It is more difficult to walk on a sandy road than on a concrete road because
A. the friction between sand and feet is less than that between concrete and feet
No: 35
Q. Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co - efficient of friction between the road and tyre is 0.2 ?
A. 14 m/s
No: 37
Q. Solar eclipse will take place when ?
A. the moon is between the sun and the earth
No: 38
Q. Isotopes of an element contain ?
A. the same number of protons but different number of neutrons
No: 39
Q. Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?
A. Scattering
No: 40
Q. In which of the following industries is mica as a raw material?
A. Electrical
No: 41
Q. Radiocarbon dating technique is used to estimate the age of
A. fossils
No: 42
Q. Lux is the SI unit of ?
A. intensity of illumination
No: 43
Q. On a rainy day, small oil films on water show brilliant colours. This is due to ?
A. interference
No: 44
Q. Point A is at a lower electrical potential than point B. An electron between them on the line joining them will ?
A. move towards B
No: 45
Q. Materials for rain - proof coats and tents owe their water - proof properties to ?
A. surface tension
No: 46
Q. RADAR is used for ?
A. detecting and locating the position of objects such as aeroplanes
No: 47
Q. Sound of frequency below 20 Hz is called ?
A. infrasonic
No: 48
Q. Supersonic plane fly with the speed ?
A. greater than the speed of sound
No: 49
Q. Mach number is used in connection with the speed of ?
A. aircraft
No: 50
Q. On a stationary sail boat, air is blown from a fan attached to the boat. The boat ?
A. does not move
No: 51
Q. Rainbow is due to ?
A. refraction and reflection of sunlight by water droplets
No: 52
Q. Stars which appear single to the naked eye but are double when seen through a telescope are ?
A. binaries
No: 53
Q. On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because ?
A. cohesion of mercury is greater than its adhesion with glass
No: 54
Q. Suitable impurities are added to a semiconductor depending on its use. This is done in order to ?
A. increase its electrical conductivity
No: 55
Q. Stars twinkle because ?
A. the refractive index of the different layers of the earth's atmosphere changes continuously, consequently the position of the image of a start changes with time
No: 56
Q. It takes much longer to cook food in the hills than in the plains, because ?
A. in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100ºC causing an increase in cooking time
No: 57
Q. Moment of inertia is ?
A. tensor
No: 58
Q. Of the following natural phenomena, tell which one known in Sanskrit as 'deer's thirst' ?
A. Mirage
No: 59
Q. Radio telescopes are better than optical telescopes because ?
A. they can detect faint galaxies which no optical telescope can, they can work even in cloudy conditions, they can work during the day and night
No: 60
Q. Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit ?
A. visible light
No: 61
Q. Out of the following pairs, which one does not have identical dimension?
A. Moment of inertia and moment of a force
No: 62
Q. Mercury is commonly used as a thermometric fluid rather than water because
A. mercury has greater visibility than water
No: 63
Q. Optical fibre works on the ?
A. total internal reflection
No: 64
Q. Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in ?
A. 4.2 years
No: 65
Q. Inside an aeroplane, flying at a high altitude ?
A. normal atmospheric pressure is maintained by the use of air pumps
No: 66
Q. Sound travels with a different speed in media. In what order does the velocity of sound increase in these media?
A. Air, water and iron
No: 67
Q. Sound travels at the fastest speed in ?
A. steel
No: 68
Q. Oil raise up the wick in a lamp. The principle involves ?
A. capillary action phenomenon
No: 69
Q. Superconductors are substances which ?
A. offer no resistance to the flow of electricity
No: 70
Q. Light travels at the fastest speed in ?
A. vaccuum
No: 71
Q. Railway tracks are banked on curves ?
A. necessary centripetal force may be obtained from the horizontal component of the weight of the train
No: 72
Q. On a cold day when a room temperature is 15ºC, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15ºC, because ?
A. metals are good conductor of heat
No: 73
Q. Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum ?
A. 3.3 km, 0.30 km
No: 74
Q. Intensity of sound at a point is ____ its distance from the source ?
A. inversely proportional to square of
No: 75
Q. Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open ?
A. at a place in a valley below sea level
No: 76
Q. The Element of an electric heater is made of ?
A. Nichrome
No: 77
Q. When water is heated from 0º Celsius to 100ºCelsius, the volume of water ?
A. First decrease , then increase
No: 78
Q. At what temperature are the temperature on Celsius and Fahrenheit scales equal ?
A. – 40º Celsius
No: 79
Q. The Period of revolution round the sun is maximum by which among the following planets ?
A. Mars
No: 80
Q. Einstein got the Nobel prize for ?
A. Photo - electric effect
No: 81
Q. Galvanometer can be converted into a voltmeter by using ?
A. High resistance in series
No: 82
Q. Gas law was given by ?
A. Boyle
No: 83
Q. Kilowatt – hour is a unit of ?
A. Power
No: 84
Q. The ozone layer protects us from ?
A. Ultra violet rays
No: 85
Q. Fire in the diesel engine is produces by which of the following ?
A. Compression
No: 86
Q. With an increase in pressure the melting point of max will ?
A. Increase
No: 87
Q. Which among the following is the best conductor of electricity ?
A. Silver
No: 88
Q. Which among the following order of decreasing wavelengths of electromagnetic waves is correct? I. Radio waves II. Infrared rays III. Visible Light IV. X - Rays ?
A. I, II, III, IV
No: 89
Q. Ampere - hour is the unit of which among the following ?
A. Amount of charge
No: 90
Q. Who discovered X - Rays ?
A. Roentgen
No: 91
Q. Which among the following are primary colors ?
A. Red, Green, Blue
No: 92
Q. At what temperature will the density of water be maximum?
A. 4º C
No: 93
Q. Persistence of vision is the principle behind ?
A. Cinema
No: 94
Q. Which metal is commonly used for making an electromagnet ?
A. Iron
No: 95
Q. Light from the laser is ?
A. Monochromatic
No: 96
Q. Choke is used to ?
A. Reduce the current in AC circuit
No: 97
Q. In a standing wave the distance between a node and adjacent antinode is ?
A. λ / 4
No: 98
Q. A telescope and microscope differ in that ?
A. Telescope has objective of large focal length and eyepiece of smaller focal lengths
No: 99
Q. The weight of a body is ?
A. Maximum at the poles
No: 100
Q. At what temperature a body will not radiate any heat energy ?
A. - 273º C
