Damp clothes are dried in spin dryers by the action of

Q1391. Damp clothes are dried in spin dryers by the action of
(a) centripetal forces
(b) centrifugal forces
(c) central forces
(d) non central forces
Ans: (b)
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Q1392. Night photography and photopraphy in mist and fog are possible using
(a) ultra-violet radiation
(b) infra-red radiation
(c) microwave radiation
(d) gamma radiation
Ans: (b)
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Q1393. A photostat machine works on
(a) electromagnetic image making
(b) electrostatic image making
(c) magnetic image making
(d) thermal image making
Ans: (b)
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Q1394. Forged documents are detected by
(a) ultraviolet rays
(b) infra-red rays
(c) beta rays
(d) gamma rays
Ans: (a)
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Q1395. Sprayer functions on
(a) Bernouli’s principle
(b) Archemede’s principle
(c) Pascal’s law
(d) Floatation principle
Ans: (a)
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Q1396. Which of the following is arranged in order of decreasing conductivity?
(a) Copper, Aluminium, Steel, Silver
(b) Aluminium, Silver, Copper, Steel
(c) Copper, Silver, Aluminium, Steel
(d) Silver, Copper, Aluminium, Steel
Ans: (d)
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Q1397. It is easier to carry two buckets of water in one hand each, than to carry only one in one hand because
(a) weights of buckets are balanced
(b) centre of gravity falls within the body
(c) centre of gravity and centre of equilibrium fall within the feet
(d) resultant weight of buckets is zero
Ans: (c)
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Q1398. An athlete runs before long jump to get advantage on
(a) Inertia of motion
(b) Frictional force
(c) Moment of a force
(d) Principle of moments
Ans: (a)
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Q1399. If a copper wire is increased to double its length, its resistance will become
(a) four times (b) one–fourth
(c) double (d) half
Ans: (c)
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Q1400. The radiation initially produced in fluorescent tube is
(a) infrared
(b) ultraviolet
(c) microwaves
(d) X-rays
Ans: (b)
Q1401. A gap is left between two rails of a railway track to accommodate……
of the metal.
(a) areal expansion
(b) volume expansion
(c) liner expansion
(d) apparent expansion
Ans: (c)
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Q1402. A pilot has to release the bomb to hit a target
(a) right above the target
(b) beyond the target
(c) before the target
(d) None of these
Ans: (c)
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Q1403. The resistance of the human body (dry condition) is of the order of
(a) 101 Ohm (b) 102Ohm
(c) 103 Ohm (d) 104 Ohm
Ans: (*)
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Q1404. Two rods, one of copper and other of steel, experience the same upthrust when placed in water.Thus, both have
(a) equal volume
(b) equal weight
(c) equal density
(d) equal mass
Ans: (a)
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Q1405. Hypermetropia or longsight can be corrected by using :
(a) Bifocal lenses
(b) Cylindrical lenses
(c) Concave lenses
(d) Convex lenses
Ans: (d)
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Q1406. In mirrors the back surface is coated with a thin layer of :
(a) Mercury (b) Silver
(c) Red oxide (d) Silver nitrate
Ans: (b)
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Q1407. The earth-wire of a cable is connected to
(a) the outer metallic body of the appliance
(b) the fuse of the appliance
(c) the filament of the appliance
(d) short circuitry of the appliance
Ans: (b)
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Q1408. Heat stored in water vapour is
(a) specific heat
(b) latent heat
(c) absolute heat
(d) relative heat
Ans: (b)
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Q1409. A periscope works on the principle of
(a) refraction
(b) total internal reflection
(c) diffraction
(d) reflection
Ans: (b)
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Q1410. Anemometer is used to measure
(a) wind direction
(b) wind velocity
(c) pressure gradient
(d) wind speed and time
Ans: (b)
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Q1411. What happens to a liquid, when the vapour pressure equals the atmospheric pressure?
(a) The liquid cools
(b) The liquid boils
(c) No change
(d) The liquid evaporates
Ans: (b)
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Q1412. Why do brids not have respiratory trouble at the time of flying at high altitude ?
(a) Their lungs are very large
(b) They fly inactively
(c) They have extra air sacs
(d) They use less oxygen
Ans: (c)
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Q1413. Conversion of heat into electrical er is achieved by using :
(a) Ammeter
(b) Hydrometer
(c) Voltmeter
(d) Thermocouple
Ans: (d)
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Q1414. Moving electric charge produces :
(a) magnetic field
(b) sound waves
(c) light rays
(d) heat waves
Ans: (a)
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Q1415. Energy in reflected light :
(a) does not depends on the angle of incidence
(b) increases with the increase in angle
(c) decreases with the increase in angle of incidence
(d) becomes maximum for angle of incidence equal to 45°
Ans: (b)
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Q1416. When a light wave is reflected from a mirror, there is a change in its
(a) frequency (b) amplitude
(c) wavelength (d) velocity
Ans: (b)
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Q1417. Safety fuse wire used in domestic electrical appliances is made of metal of low
(a) Resistance
(b) Melting point
(c) Specific gravity
(d) Conductance
Ans: (b)
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Q1419. Which type of mirror is used in the head lights of vehicles ?
(a) Plane mirror
(b) Concave mirror
(c) Convex mirror
(d) Parabolic mirror
Ans: (b)
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Q1420. Shaving mirror is
(a) Convex (b) Concave
(c) Plane (d) Parabolic
Ans: (b)