GK in English

GK Chapterwise – CDS Previous Year Papers

Table of Contents

81. Dirty cloths containing grease and oil stains are cleaned by adding detergents to water. Stains are removed because detergent

(a)reduces drastically the surface tension between water and oil
(b) increases the surface tension between water and oil
(c) increases the viscosity of water and oil
(d) decreases the viscosity in detergent mixed water
Ans: (a)

CDS (I) 2018

82. Motion of an oscillating liquid column in a U-tube is

(a)periodic but not simple harmonic
(b) non-periodic
(c) simple harmonic and time period is independent of the density of the liquid
(d) simple harmonic and time period depends on the density of the liquid
Ans: (c)
CDS Exam (I) 2016

83. A ray of white light strikes the surface of an object. If all the colours are reflected the surface would appear

(a)black
(b) white
(c) grey
(d) opaque
Ans: (b)

CDS (I) 2008

84. The position, relative size and nature of the image formed by a concave lens for an object placed at infinity are respectively

(a)at focus, diminished and virtual
(b) at focus, diminished and real
(c) between focus and optical centre, diminished and virtual
(d) between focus and optical centre, magnified and real
Ans: (a)

CDS (II) 2010

85. No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be

(a)either plane or convex
(b) plane only
(c) concave
(d) convex only
Ans: (a)

CDS (I) 2015

86. A mobile phone charger is

(a)an inverter
(b) a UPS
(c) a step-down transformer
(d) a step-up transformer
Ans: (c)
CDS Exam (I) 2011

87. Two layers of a cloth of equal thickness provide warmer covering than a single layer of cloth with double the thickness. Why?

(a)Because of the air encapsulated between two layers
(b) Since effective thickness of two layers is more
(c) Fabric of the cloth plays the role
(d) Weaving of the cloth plays the role
Ans: (a)

CDS (I) 2013

88. In cricket match, while catching a fast moving ball, a fielder in the ground gradually pulls his hands backwards with the moving ball to reduce the velocity to zero. The act represents

(a)Newton’s first law of motion
(b) Newton’s second law of motion
(c) Newton’s third law of motion
(d) Law of conservation of energy
Ans: (b)

CDS (II) 2017

89. An oscilloscope is an instrument which allows us to see waves produced by

(a)Visible light
(b) X-rays
(c) Sound
(d) Gamma rays
Ans: (c)

CDS (I) 2015

90. In the phenomenon of dispersion of light, the light wave of shortest wavelength is

(a)accelerated and refracted the most
(b) slowed down and refracted the most
(c) accelerated and refracted the least
(d) slowed down and refracted the least
Ans: (b)
CDS Exam (I) 2019

91. Inactive Nitrogen and Argon gases are usually used in electric bulbs in order to

(a)increase the intensity of light emitted
(b) increase the life of the filament
(c) make the emitted light coloured
(d) make the production of bulb economical
Ans: (b)

CDS (I) 2012

92. Tungsten is used for the construction of filament in electric bulb because of its

(a)high specific resistance
(b) low specific resistance
(c) high light emitting power
(d) high melting point
Ans: (d)

CDS (II) 2007

93. The upper and lower portions in common type of bi-focal lenses are respectively

(a)concave and convex
(b) convex and concave
(c) both concave of different focal lengths
(d) both convex of different focal lengths
Ans: (a)
CDS Exam (II) 2009

94. Statement I: When a gun is fired it recoils, i.e., it pushes back, with much less velocity than the velocity of the bullet.
Statement II: Velocity of the recoiling gun is less because the gun is much heavier than the bullet.

(a)Both the statements are true and statement II is the correct explanation of statement I
(b) Both the statements are true, but statement II is not the correct explanation of statement I
(c) Statement I is true, but statement II is false
(d) Statement I is false, but statement II is true
Ans: (a)
CDS Exam (I) 2018

95. For a harmonic oscillator, the graph between momentum p and displacement q would come out as

(a)a straight line
(b) a parabola
(c) a circle
(d) an ellipse
Ans: (d)

CDS (I) 2016

96. distance time The distance-time graph for an object is shown above.
Which one of the following statements holds true for this object ?

(a)The object is moving with uniform speed
(b) The object is at rest
(c) The object is having non-linear motion
(d) The object is moving with non-uniform speed
Ans: (b)

CDS (II) 2008

97. The distribution of electrons into different orbits of an atom, as suggested by Bohr; is

(a)2 electrons in the K-orbit, 6 electrons in the L-orbit, 18 electrons in the M-orbit
(b) 2 electrons in the K-orbit, 8 electrons in the L-orbit, 32 electrons in the M-orbit
(c) 2 electrons in the K-orbit, 8 electrons in the L-orbit, 18 electrons in the M-orbit
(d) 2 electrons in the K-orbit, 8 electrons in the L-orbit, 16 electrons in the M-orbit
Ans: (c)

CDS (II) 2015

98. An electron and a proton are circulating with same speed in circular paths of equal radius. Which one among the following will happen, if the mass of a proton is about 2,000 times that of an electron ?

(a)The centripetal force required by the electron is about 2,000 times more than that required by the proton
(b) The centripetal force required by the proton is about 2,000 times more than that required by the electron
(c) No centripetal force is required for any charged particle
(d) Equal centripetal force acts on both the particles as they rotate in the same circular path
Ans: (b)

CDS (I) 2011

99. Creation of something from nothing is against the law of

(a)constant proportions
(b) conservation of mass-energy
(c) multiple proportions
(d) conservation of momentum
Ans: (b)

CDS (II) 2013

100. In respect of the difference of the gravitational force from electric and magnetic forces, which one of the following statements is true ?

(a)Gravitational force is stronger than the other two.
(b) Gravitational force is attractive only, whereas the electric and the magnetic forces are attractive as well as repulsive.
(c) Gravitational force has a very short range.
(d) Gravitational force is a long range force, while the other two are short range forces.
Ans: (b)
CDS Exam (II) 2017

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