GK in English

GK Chapterwise – CDS Previous Year Papers

Table of Contents

141. Which one of the following statements is not correct?

(a)The cathode rays originate from cathode and proceed towards the anode in a cathode-ray discharge tube.
(b) The television picture tubes are nothing but cathoderay tubes.
(c) The cathode rays themselves are not visible.
(d) The characteristics of cathode rays depend upon the nature of the gas present in the cathode-ray tube.
Ans: (d)
CDS Exam (I) 2019

142. The optical phenomenon that is primarily responsible for the observation of rainbow on a rainy day is

(b) interference
(c) dispersion
(d) reflection
Ans: (c)

CDS (I) 2012

143. Ultrasonic waves are produced by making use of

(a)ferromagnetic material
(b) ferrimagnetic material
(c) piezoelectric material
(d) pyroelectric material
Ans: (c)

CDS (II) 2007

144. Joule-Thomson process is extremely useful and economical for attaining low temperature. The process can be categorized as
(b) isobaric process
(b) isoenthalpic process
(c) adiabatic process
(d) isochoric process
Ans: (c)

CDS (I) 2009

145. Which one of the following types of glasses is used for making optical instruments?

(a)Pyrex glass
(b) Soft glass
(c) Hard glass
(d) Flint glass
Ans: (c)
CDS Exam (I) 2018

146. A person is standing on a frictionless horizontal ground.
How can he move by a certain distance on this ground?

(a)By sneezing
(b) By jumping
(c) By running
(d) By rolling
Ans: (a)

CDS (I) 2016

147. After using for some time, big transformers get heated up.
This is due to the fact that
1. current produces heat in the transformers
2. hysteresis loss occurs in the transformers
3. liquid used for cooling gets heated Select the correct answer using the code given below.

(a)1 only
(b) 2 and 3 only
(c) 1 and 2 only
(d) 1, 2 and 3
Ans: (d)

CDS (II) 2008

148. Which one of the following is the correct relation between the Kelvin temperature (T) and the Celsius temperature (tc)?

(a)These are two independent temperature scales
(b) T = tc
(c) T = tc – 273.15
(d) T = tc + 273.15
Ans: (d)

CDS (I) 2010

149. Why is argon gas used along with tungsten wire in an electric bulb?

(a)To increase the life of the bulb
(b) To reduce the consumption of electricity
(c) To make the emitted light colored
(d) To reduce the cost of the bulb
Ans: (a)
CDS Exam (I) 2015

150. Which one of the following elements is used as a timekeeper in atomic clocks?

(b) Caesium
(c) Calcium
(d) Magnesium
Ans: (b)

CDS (I) 2011

151. Desalination of seawater is done by using reverse osmosis.
The pressure applied to the solution is

(a)larger than osmotic pressure
(b) smaller than osmotic pressure
(c) equal to osmotic pressure
(d) equal to atmospheric pressure
Ans: (a)

CDS (II) 2013

152. Which of the following represents a relation for ‘heat lost = heat gained’?

(a)Principle of thermal equilibrium
(b) Principle of colors
(c) Principle of calorimetry
(d) Principle of vaporization
Ans: (c)
CDS Exam (I) 2015

153. Working of safety fuses depends upon
1. magnetic effect of the current
2. chemical effect of the current
3. magnitude of the current
4. heating effect of the current Select the correct answer using the code given below.

(a)1, 2, 3 and 4
(b) 1, 2 and 3 only
(c) 3 and 4 only
(d) 4 only
Ans: (c)

CDS (I) 2019

154. Consider the following statements:
1. There is no net moment on a body which is in equilibrium.
2. The momentum of a body is always conserved.
3. The kinetic energy of an object is always conserved.
Which of the statements given above is/are correct?

(a)1, 2 and 3
(b) 2 and 3 only
(c) 1 and 2 only
(d) 1 only
Ans: (c)

CDS (II) 2012

155. Which one of the following is the value of one nanometer?

(a)10–7 cm
(b) 10–6 cm
(c) 10–4 cm
(d) 10–3 cm
Ans: (a)
CDS Exam (II) 2007

156. Sound waves cannot travel through a

(a)copper wire placed in air
(b) silver slab placed in air
(c) glass prism placed in water
(d) wooden hollow pipe placed in vacuum
Ans: (d)

CDS (II) 2009

157. The pressure of a fluid varies with depth h as P = P0 + rgh, where r is the fluid density. This expression is associated with

(a)Pascal’s law
(b) Newton’s law
(c) Bernoulli’s principle
(d) Archimede’s principle
Ans: (a)

CDS (II) 2018

158. A wire of copper having length l and area of cross-section A is taken and a current I is flown through it. The power dissipated in the wire is P. If we take an aluminium wire having same dimensions and pass the same current through it, the power dissipated will be

(b) < P (c) > P
(d) 2P
Ans: (c)
CDS Exam (II) 2016

159. When the Sun is near the horizon during the morning or evening, it appears reddish. The phenomenon that is responsible for this observation is

(a)reflection of light
(b) refraction of light
(c) dispersion of light
(d) scattering of light
Ans: (d)

CDS (II) 2008

160. Two metallic wires made from copper have same length but the radius of wire 1 is half of that of wire 2. The resistance of wire 1 is R. If both the wires are joined together in series, the total resistance becomes

(b) R 2
(c) 5 R 4
(d) 3 R 4
Ans: (c)

CDS (I) 2010

Chapter 6 Chemistry

1. Match List I with List II and select the correct answer using the codes given below the Lists. Lis t I List II
(Mineral) (Indus tries in which largely used)
A. Limes tone 1 Cement
B. Copper 2 Electrical goods
C. Bauxite 3 Manufacture of aeroplanes
D. Manganese 4 Steel Codes A B C D
(a)3 4 1 2
(b) 1 2 3 4
(c) 3 2 1 4
(d) 1 4 3 2
Ans: (b)

CDS (I) 2015

2. German silver is an alloy of

(a)gold and silver
(b) copper and silver
(c) copper, zinc and silver
(d) copper, zinc and nickel
Ans: (d)

CDS (II) 2011

3. ‘Freon’ used as refrigerants is chemically known as

(a)chlorinated hydrocarbon
(b) fluorinated hydrocarbon
(c) chlorofluoro hydrocarbon
(d) fluorinated aromatic compound
Ans: (c)
CDS Exam (II) 2013

4. In which categories did Marie Curie win her two different Nobel prizes?

(a)Physics and Chemistry
(b) Chemistry and Medicine
(c) Physics and Medicine
(d) Chemistry and Peace
Ans: (a)

CDS (II) 2017

5. Nail varnish remover generally contains which one of the following?

(b) Benzene
(c) Methyl alcohol
(d) Acetone
Ans: (d)

CDS (I) 2015

6. The flavour of apple is mainly due to which one of the following?

(b) Benzene
(c) Ethanol
(d) Benzaldehyde
Ans: (c)
CDS Exam (I) 2019

7. An -particle consists of which of the following?

(a)2 protons and 2 neutrons
(b) 1 proton and 1 electron
(c) 2 protons and 4 neutrons
(d) 1 proton and 1 neutron
Ans: (a)
CDS Exam (II) 2012

8. Which of the following isotopes of carbon is/are used in carbon dating?

(a)6C12 only
(b) 6C13 only
(c) 6C14 only
(d) 6C12 and 6C14
Ans: (c)

CDS (II) 2007

9. Which one of the following is involved for desalination of sea water?

(a)Reverse osmosis
(b) Simple osmosis
(c) Use of sodium aluminium silicate as zeolite
(d) Use of ion selective electrodes
Ans: (a)

CDS (I) 2009

10. Which of the following metals are present in haemoglobin and chlorophyll, respectively?

(a)Fe and Mg
(b) Fe and Zn
(c) Mg and Zn
(d) Zn and Mg
Ans: (a)
CDS Exam (I) 2018

11. The tracking of people by trained dogs is based on the recognisation of which of the following compounds in the sweat from feet?

(a)Carboxylic acids
(b) Uric acid
(c) Sugar
(d) Salt
Ans: (a)

CDS (I) 2016

12. As which one of the following, does carbon occur in its purest form in nature?

(a)Carbon black
(b) Graphite
(c) Diamond
(d) Coal
Ans: (a)

CDS (II) 2008

13. What is the purpose of adding baking soda to dough?

(a)To generate moisture
(b) To give a good flavour
(c) To give good colour
(d) To generate carbon dioxide
Ans: (d)

CDS (I) 2010

14. Consider the following statements
1. Nitric acid is used in the production of fertilizers.
2. Sulphuric acid is used in the production of explosives.
Which of the statements given above is/are correct?

(a)Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 nor 2
Ans: (c)
CDS Exam (I) 2015

15. Which one of the following metals is less reactive than hydrogen?

(b) Copper
(c) Lead
(d) Magnesium
Ans: (b)

CDS (I) 2011

16. Which one of the following substances is made from natural raw materials?

(b) Nylon
(c) Polyester
(d) Polystyrene
Ans: (a)

CDS (II) 2013

17. Which one of the following substances is used in the manufacture of safety matches?

(a)Red phosphorus
(b) White phosphorus
(c) Phosphorus trioxide (P203)
(d) Black phosphorus
Ans: (a)

CDS (I) 2017

18. Which one of the following is an element?

(b) Diamond
(c) Ruby
(d) Sapphire
Ans: (b)
CDS Exam (I) 2015

19. What is the pH value of pure water?

(b) 6
(c) 7
(d) 10
Ans: (c)

CDS (I) 2019

20. ‘Misch metal’ is widely used in the manufacture of which of the following?

(a)Material of car brake
(b) Smoke detectors
(c) Cigarette lighters
(d) Emergency lights
Ans: (c)

CDS (II) 2012

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