Free & Premium Study Material · Online Courses · Instant Download+91 99398 78821 · support@downloadstore.in
downloadstoreSTUDY MATERIAL
LoginRegister🛒0

Mechanics

219 MCQ questions with answers and explanations · page 4 of 9

Test yourself▶ 25 question test▶ 50 question test

Q76. Will remain unchanged when the quantity of the substance changes?

  1. Avolume
  2. BBurden
  3. CMass
  4. Ddensity
Show answer & explanation

Answer: D) density

Q77. Why does a swimmer find it easier to swim in sea water than in river water?

  1. AReduces pollution in sea water
  2. BSea waves help a swimmer to float
  3. CSea water has a higher density than ordinary water.
  4. DThe ocean has a larger volume of water
Show answer & explanation

Answer: C) Sea water has a higher density than ordinary water.

Q78. Why do clouds float in the atmosphere?

  1. Alow pressure
  2. Blow density
  3. Clow viscosity
  4. Dlow temperature
Show answer & explanation

Answer: B) low density

Q79. How much of an iceberg floating in the ocean remains above the sea surface?

  1. A0.11111111111111
  2. B0.1
  3. C0.16666666666667
  4. D0.25
Show answer & explanation

Answer: B) 0.1

Q80. The wall below the dam is made thick because-

  1. AThe pressure of the liquid increases with increasing depth
  2. Bfluid pressure decreases with increasing depth
  3. CThe density of the liquid increases with increasing depth.
  4. DThe density of a liquid decreases with increasing depth
Show answer & explanation

Answer: A) The pressure of the liquid increases with increasing depth

Q81. Skating on ice demonstrates that the melting point of ice increases with increasing pressure.

  1. Aincreases
  2. Bhappens to
  3. Cremains unchanged
  4. Dfirst decreases then increases
Show answer & explanation

Answer: B) happens to

Q82. The ball keeps dancing in the water spray at the intersections because-

  1. AAs the velocity of water increases, the pressure decreases.
  2. BThe higher the velocity of the water, the higher the pressure
  3. Cdue to the surface tension of water
  4. Ddue to the viscosity of water
Show answer & explanation

Answer: A) As the velocity of water increases, the pressure decreases.

Q83. Heavy icebergs melt from the bottom rather than the top because-

  1. AThe temperature of the lower floor is higher
  2. BThe melting point decreases due to higher pressure at the bottom.
  3. CIce is not a real solid.
  4. Dnone of the above
Show answer & explanation

Answer: B) The melting point decreases due to higher pressure at the bottom.

Q84. A person trapped in a swamp is advised to lie down because-

  1. AThe pressure decreases as the area increases
  2. BDue to greater area, the pressure increases.
  3. CThere is no relation between pressure and area.
  4. DFor all the reasons mentioned above
Show answer & explanation

Answer: A) The pressure decreases as the area increases

Q85. When two pieces of ice are pressed together, they stick together because-

  1. AThe melting point of ice decreases due to increased pressure.
  2. BThe melting point of ice increases with increasing pressure
  3. CDue to high pressure, the melting point of ice first decreases and then increases.
  4. DThere is no relation between pressure and melting point.
Show answer & explanation

Answer: A) The melting point of ice decreases due to increased pressure.

Q86. Often, light thatched or tin roofs are blown away during a strong storm because-

  1. ARoofs have complex shapes
  2. BRoofs are not tightly fastened
  3. CHigh velocity air flowing over the roof creates pressure on the roof surface and the pressure below the roof remains normal.
  4. DThatched roofs blow away by strong winds
Show answer & explanation

Answer: C) High velocity air flowing over the roof creates pressure on the roof surface and the pressure below the roof remains normal.

Q87. Wide strips of wood or concrete are placed under the railway track, so that-

  1. AIt can absorb shocks
  2. BTo apply fish fillets correctly
  3. Ckeep the tracks parallel
  4. DThe pressure exerted by the train is reduced
Show answer & explanation

Answer: D) The pressure exerted by the train is reduced

Q88. Sometimes people start bleeding from their nose and mouth in the mountains because-

  1. ABlood pressure increases with altitude
  2. Bblood pressure decreases with increasing altitude
  3. Catmospheric pressure increases with increasing altitude
  4. Datmospheric pressure decreases with increasing altitude
Show answer & explanation

Answer: D) atmospheric pressure decreases with increasing altitude

Q89. Ink comes out of fountain pen in an aeroplane because-

  1. Aair pressure decreases with increasing altitude
  2. BAir pressure increases with increasing altitude
  3. CAir pressure remains unchanged with increasing altitude
  4. Dnone of the above
Show answer & explanation

Answer: A) air pressure decreases with increasing altitude

Q90. If the mass of the Earth remains the same and the radius decreases by 1%, then the value of 'g' on the surface of the Earth-

  1. Awill increase by 0.5%
  2. Bwill increase by 2%
  3. Cwill decrease by 0.5%
  4. Dwill decrease by 2%
Show answer & explanation

Answer: B) will increase by 2%

Q91. Why does water boil at temperatures below 100°C at high altitudes?

  1. ABecause atmospheric pressure decreases, the boiling point decreases.
  2. Bbecause gravity is low
  3. CDue to heavy winds in the mountains
  4. DNone of the above is correct
Show answer & explanation

Answer: A) Because atmospheric pressure decreases, the boiling point decreases.

Q92. The pressure inside a soap bubble

  1. Ais greater than atmospheric pressure
  2. BIt is less than atmospheric pressure.
  3. Cis equal to atmospheric pressure
  4. Dis half the atmospheric pressure
Show answer & explanation

Answer: A) is greater than atmospheric pressure

Q93. Why do we slip on muddy roads?

  1. Adue to gravitational force
  2. Bdue to relative velocity
  3. Cdue to lack of friction
  4. Ddue to excessive friction
Show answer & explanation

Answer: C) due to lack of friction

Q94. When the mercury in the barometer suddenly falls, what does it indicate?

  1. Ahot weather
  2. Bchilly weather
  3. Cpossibility of thunderstorms
  4. Ddry season
Show answer & explanation

Answer: C) possibility of thunderstorms

Q95. polythene balloon filled with hydrogen is released from the earth's surface. As it rises higher in the atmosphere-

  1. Athe size of the balloon will decrease
  2. BThe balloon will flatten into a disc shape.
  3. CThe size of the balloon will increase
  4. DThe size and shape of the balloon will remain the same.
Show answer & explanation

Answer: C) The size of the balloon will increase

Q96. Why is it more difficult to breathe in the mountains than on the plains?

  1. AAs altitude increases, air pressure decreases and oxygen requirement increases.
  2. BMountain air is heavy and cannot be filled into the lungs.
  3. CMountain air is impure, so we cannot breathe it.
  4. Dnone of the above
Show answer & explanation

Answer: A) As altitude increases, air pressure decreases and oxygen requirement increases.

Q97. When the Fortin barometer is taken to a high mountain, the mercury in the tube falls because-

  1. AThe air here is relatively light.
  2. BWith decrease in temperature the mercury level decreases
  3. CThe atmospheric pressure there is low
  4. Dthere the surface tension decreases
Show answer & explanation

Answer: C) The atmospheric pressure there is low

Q98. Before take-off, the airplane is run on the race track of-

  1. Ato reduce the working air pressure
  2. BTo increase the working air pressure
  3. CTo reduce the frictional force between the aircraft and the ground
  4. DTo increase the frictional force between the ground and the air by using air pressure
Show answer & explanation

Answer: B) To increase the working air pressure

Q99. A rubber balloon filled with hydrogen bursts when it goes up in the air because-

  1. AThe weight of hydrogen increases
  2. Bair pressure increases
  3. CThe pressure of hydrogen decreases
  4. DThe air pressure decreases.
Show answer & explanation

Answer: D) The air pressure decreases.

Q100. Food is cooked in less time in a pressure cooker because-

  1. AThe temperature of boiling water decreases due to high pressure.
  2. BIt is closed from all sides and hence is not affected by wind.
  3. CThe temperature of boiling water increases due to higher pressure.
  4. DThere is very little evaporation of the water used.
Show answer & explanation

Answer: C) The temperature of boiling water increases due to higher pressure.

123456…9
← MagnetismMiscellaneous Physics →
💬