Railway tracks are banked on curves so that

Q1421. Railway tracks are banked on curves so that
(a) Necessary centrifugal force may be obtained from the horizontal component of the weight of the train
(b) No frictional force may be produced between the tracks and the wheels of the train
(c) Necessary centripetal force may be obtained from the horizontal component of the weight of the train
(d) The train may not fall down inwards
Ans: (c)
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Q1422. A fuse wire is made of:
(a) an alloy of tin and copper
(b) an alloy of tin and lead
(c) an alloy of tin and aluminium
(d) an alloy of nickel and chromium
Ans: (b)
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Q1423. Fat can be separated from milk in a cream separator because of:
(a) Cohesive force
(b) Gravitational force
(c) Centripetal force
(d) Centrifugal force
Ans: (d)
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Q1424. The head mirror used by ENT doctors is
(a) Concave (b) Convex
(c) Plane (d) Plano-convex
Ans: (a)
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Q1425. Ultra violet light of Sun’s radiation is prevented from reaching the earth’s atmosphere by the layer of
(a) Oxygen (b) Hydrogen
(c) Ozone (d) Helium
Ans: (c)
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Q1426. The blue colour of sky is due to
(a) reflection of sunlight
(b) refraction of sunlight
(c) scattering of shorter wavelengths of sunlight in the atmosphere
(d) scattering of longer wavelengths of sunlight in the atmosphere
Ans: (c)
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Q1427. If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is
(a) Height of the liquid column
(b) Surface area of the bottom of the vessel
(c) Density of the liquid
(d) Acceleration due to gravity at the bottom of the vessel
Ans: (b)
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Q1428. A stone is dropped from the roof of a house towards the ground.
The kinetic energy of the stone will be maximum:
(a) just after it is dropped
(b) when it is just on the half-way
(c) just before it touches the ground
(d) when it touches the ground
Ans: (c)
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Q1429. If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is
(a) Height of the liquid column
(b) Surface area of the bottom of the vessel
(c) Density of the liquid
(d) Acceleration due to gravity at the bottom of the vessel
Ans: (b)
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Q1430. Water is used in hot water bags because
(a) It is easily obtained
(b) It is cheaper and is not harmful
(c) It has high specific heat
(d) It is easy to heat water
Ans: (c)
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Q1431. Electro-static precipitator is used to control
(a) Chemical Pollutants
(b) Radio-active Pollutants
(c) Water Pollutants
(d) Air Pollutants
Ans: (d)
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Q1432. An instrument that records earthquakes is
(a) Ergograph
(b) Ediograph
(c) Thermograph
(d) Seismograph
Ans: (d)
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Q1433. A small gap is left at the joints of rails in a railway track to
(a) avoid the tracks being distorted due to seasonal temperature variation
(b) avoid the heating of tracks to high temperature
(c) control the speed of train
(d) keep the rails equidistant
Ans: (a)
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Q1434. 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
Ans: (c)
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Q1435. When hot liquid is poured into a thick glass tumbler, it cracks because glass :
(a) is a bad conductor of heat so only inner surface expands
(b) has high temperature coefficient of expansion
(c) has a very low specific heat
(d) has low temperature coefficient of expansion
Ans: (a)
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Q1436. If cream is removed from milk, its density
(a) Increases
(b) Decreases
(c) Remains the same
(d) May increase or decrease
Ans: (a)
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Q1437. Indicate the false statement about the resistance of a wire
(a) it depends on material of wire
(b) it is directly proportional to the length of wire
(c) it is directly proportional to the area of cross-section of wire
(d) resistance of metallic wire increases with increase in temperature
Ans: (c)
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Q1438. X-rays region lies between
(a) Ultraviolet and visible region
(b) Visible and infra-red region
(c) Gamma-rays and ultraviolet region
(d) Short radio waves and long radio waves
Ans: (c)
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Q1439. Pressure Cooker cooks faster because
(a) boiling point decreases with rise of pressure
(b) it cooks the food at low pressure
(c) higher temperature is attained for cooking
(d) the material of the cooker is a good conductor
Ans: (c)
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Q1440. In the remote control of television, electromagnetic waves used are
(a) ultraviolet (b) microwave
(c) radiowave (d) infrared
Ans: (d)
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Q1441. The characteristic invalid for heat radiation is that it travels :
(a) in a straight line
(b) in all directions
(c) with the speed of light
(d) heating the medium through which it passes
Ans: (c)
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Q1442. In a water lifting electric pump, we convert
(a) Electrical energy into Potential energy
(b) Kinetic energy into Electrical energy
(c) Kinetic energy into Potential energy
(d) Electrical energy into Kinetic energy
Ans: (a)
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Q1443. Magnetic keepers are pieces of
(a) Nickel (b) Cobalt
(c) Steel (d) Soft iron
Ans: (d)
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Q1444. One bar is equal to
(a) 103 Pa (b) 100 Pa
(c) 105 Pa (d) 104 Pa
Ans: (c)
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Q1445. Man perceives sound vibrations in the frequency ranges of
(a) 0 – 5 Hz (b) 6 – 10 Hz
(c) 11 – 15 Hz
(d) 20 – 20000 Hz
Ans: (d)
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Q1446. 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
Ans: (c)
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Q1447. Time of exposure required for taking photograph of an object depends upon the
(a) brightness of the object
(b) skill of photographer
(c) proximity of object
(d) size of the object
Ans: (a)
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Q1448. Fiber optics cable used in communication, works on the principle of
(a) regular reflection of light
(b) diffuse reflection of light
(c) refraction of light
(d) total internal reflection of light
Ans: (d)
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Q1449. A television channel is characterised by
(a) frequency of transmitted signal
(b) velocity of transmitted signal
(c) physical dimension of television screen
(d) size of picture tube
Ans: (a)
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Q1450. The colour of sky appears blue due to
(a) reflection (b) refraction
(c) scattering of shorter wave lengths
(d) dispersion
Ans: (c)