Combined Defence Services Examination 2021 - I Solved Paper
Solved Question Paper - General Knowledge - Exam held on 07 February 2021
Click on the Show Answer button to see the answer.
1. Which one of the following statements is not correct?
Real GDP is calculated by valuing outputs of different years at common prices.
Potential GDP is the real GDP that the economy would produce if its resources were fully employed.
Nominal GDP is calculated by valuing outputs of different years at constant prices.
Real GDP per capita is the ratio of real GDP divided by population.
Answer (c).
2. The mismatch in the regional or occupational pattern of job vacancies and the pattern of worker availability results in
Structural unemployment
Disguised unemployment
Altered unemployment
Cyclical unemployment
Answer (a).
3. The situation in an economy which is growing slowly along with rapid inflation (rising price level) is called
Stagnation
Deflation
Stagflation
Recession
Answer (c).
4. The increase in private investment spending induced by the increase in Government spending is known as
Crowding in
Deficit financing
Crowding out
Pumping out
Answer (a).
5. The asset or assets that a borrower pledges in order to guarantee repayment of loan is called as
Cheque
Collateral
Guarantee card
Bond
Answer (b).
6. The percentage by which the money the borrower pays back exceeds the money that was borrowed is called as
Bank rate
Nominal interest rate
Real interest rate
Terms of credit
Answer (b).
7. Which one of the following statements about the Gandhi-Irwin Pact of 1931 is correct?
The Government would not release those prisoners who had been non-violent.
The Government would not release those prisoners who had indulged in the peaceful picketing of liquor and foreign cloth shops.
The Congress did not agree to the suspension of the Civil disobedience Movement.
The Congress agreed to take part in the Second Round Table Conference.
Answer (d).
8. Who among the following founded the Bhil Seva Mandal in 1922?
Dayaram Gidumal
Gurusaday Dutt
Dhondo Keshav Karve
Amritlal Vithaldas Thakkar
Answer (d).
9. In 1911, who among the following introduced a bill in the Imperial Legislative Council for introduction of compulsory and free primary education in India?
Dadabhai Naoroji
Bal Gangadhar Tilak
Sir Harcourt Butler
Gopal Krishna Gokhale
Answer (d).
10. Which one of the following statements about the Act V of 1843 relating to Slavery in India is correct?
It gave the masters the right to wilfully keep their slaves tied to their estates.
It denied the masters the use of Courts to assert their claims on slaves.
The Law Courts and masters worked jointly in resolving the cases of desertion.
The slaves became the owners of the land.
Answer (b).
11. Which Maratha statesman signed the Treaty of Bassein on December 31, 1802?
Baji Rao II
Vithuji Holkar
Daulat Rao Sindhia
Madhava Rao Narayan
Answer (a).
12. The Amara-Nayaka system was a major political innovation of which Indian imperial rulers?
Cholas
Chalukyas
Guptas
Vijayanagara
Answer (d).
13. KIRAN (Knowledge Involvement in Research Advancement through Nurturing) is an initiative to provide opportunites to women scientists who?
had a break in their career due to family reasons.
are pursuing innovative research in life sciences.
have collaborative projects with labs in foreign countries.
have leading edge projects in Nano-Science and Technology
Answer (a).
14. NIDHI is an umbrella scheme for the promotion of
young and aspiring innovators.
scientific research.
primary health care.
primary education in rural areas.
Answer (a).
15. The Saubhagya Scheme aims at universal
LPG connection.
household electrification.
primary school education.
public health insurance.
Answer (b).
16. Mission Indradhanush aims at
reducing child deaths due to pneumonia.
reducing the impact of rotavirus.
elimination of maternal tetanus.
full immunisation of children.
Answer (d).
17. Which one of the following statements about the DDU - GKY is not correct?
It is a skill training programme.
It is for rural youth from poor families.
Its objective is placement in wage employment.
It relies entirely on skill training by Government agencies.
Answer (d)
18. Which of the following statements about the Pradhan Mantri Gram Sadak Yojana are correct?
It is part of Government of India's poverty reduction strategy.
It is a centrally sponsored scheme for rural development.
It provides connectivity in rural areas.
Select the correct answer using the code given below:
1, 2 and 3
1 and 3 only
2 and 3 only
1 and 2 only
Answer (a).
19. India's territorial limit extends towards the sea upto
10 nautical miles
12 nautical miles
14 nautical miles
15 nautical miles
Answer (b).
20. Which one of the following is a cold ocean current?
Brazilian Current
Gulf Stream
North Equatorial Current
California Current
Answer (d).
21. Identify the type of soil on the basis of the given characteristics:
They are rich in lime, iron, magnesia and alumina.
They are generally clayer, deep and impermeable.
They are mainly found in Maharashtra, Madhya Pradesh and Gujarat.
Select the correct answer using the code given alternatives:
Laterite soil
Red and yellow soil
Saline soil
Black soil
Answer (d).
22. Arabica, Robusta and Liberica are varieties of
Coffee
Tea
Sugarcane
Cotton
Answer (a)
23. Aluminium is manufactured from
Copper ore
Bauxite ore
Mica ore
Manganese ore
Answer (b).
24. Which one of the following sea ports gained significance for handling iron-ore exports to Japan?
Kandla
Ennore
Kochi
Mormugao
Answer (d).
25. Which of the following is not a function of money?
Acts as an intermediate in the exchange process
Acts as a store of value
Used as the unit of account
Used for regulating consumption
Answer (d).
26. The situation where the equilibrium level of real GDP falls short of potential GDP is known as
Recessionary gap
Inflationary gap
Demand-side inflation
Supply-side inflation
Answer (a).
27. The excess of total expenditure of Government over its total receipts, excluding borrowings is known as
Primary deficit
Fiscal deficit
Current deficit
Capital deficit
Answer (b).
28. Exchange rates state the value of one currency in terms of other currencies. Which one of the following statements with respect to the exchange rate of currency is correct?
Floating exchange rates are rates in which the Governments interfere by buying or selling their currencies.
Fixed exchange rates are rates set by Government decisions and maintained by Government actions.
Under the Bretton Woods System, the exchange rates are floated in terms of rise or fall in price of gold.
Under the classical gold standard, the exchange rates are fixed in terms of price of dollar.
Answer (b).
29. Francois Bernier was physician to
Prince Murad
Princess Jahanara
Experor Shah Jahan
Prince Dara Shikoh
Answer (d).
30. Which one of the following British firms was taken over by Soorajmull-Nagarmull group?
McLeod
Ocavious Steel
Davenport
Andrew Yule
Answer (a).
31. Which one of the following statements with regard to ryotwari settlement is not correct?
In southern and western India, the ryotwari settlement was adopted.
Ryotwari was in principle a direct contract between the ryot and the state.
It means a tax contract valid for usually 30 years.
In principle, it strengthened the former elite, the zamindars and weakened the peasantry.
Answer (d).
32. Which one of the following statements about the British Indian Medical Service (IMS) is not correct?
IMS began in 1784.
It recruited health professionals by means of a competitive examination.
Indians were never admitted to IMS.
The IMS was at first meant to look after the troops
Answer (c).
33. When was the monopoly of China trade lost by East India Company?
1813
1833
1838
1860
Answer (b).
34. National Disaster Management Authority is headed by
the Prime Minister
the Home Minister
the President
the Health Minister
Answer (a).
35. Which of the following statements regarding the 'casting vote' in the Parliament is/are correct?
It is cast by the speaker or a person acting as such.
It is cast in addition to voting in the first instance.
It is cast in the case of equality of votes.
It is always cast to maintain the status quo.
Select the correct answer using the code given below:
1, 2 and 3 only
1 and 3 only
2 and 4 only
3 only
Answer (b).
36. Equality before the law or equal protection of the laws within the territory of India is guaranteed under which one of the following Articles of the Constitution of India?
Article 14
Article 15
Article 16
Article 22
Answer (a).
37. 'Legal Positivism' theory was developed by
T.H. Green
Thomas Hobbes
John Austin
Patrick Devlin
Answer (c).
38. Who among the following said that Democracy means a system of 'Government by Consent'?
John Locke
J.S. Mill
Jeremy Bentham
J.J. Rousseau
Answer (a).
39. Milpa and Ladang are different names for
shifting cultivation.
mixed farming.
truck farming.
plantation agriculture.
Answer (a).
40. Which one of the following approaches of human development was initially proposed by the International Labour Organisation (ILO) and emphasised on health, education, food, water supply, sanitation and housing?
Welfare approach
Basic needs approach
Income approach
Capability approach
Answer (b).
41. Which one of the following tributaries of river Indus feeds the canal system of the Bhakra Nangal Project?
Chenab
Satluj
Ravi
Jhelum
Answer (b).
42. When the rivers discharge their waters from all directions into a lake or depression, the pattern is known as
Trellis
Dendritic
Radial
Centripetal
Answer (d).
43. Which one of the following statements about the Coriolis force is not correct?
It is maximum at the Poles.
It is absent at the Equator.
It deflects the wind to the right direction in the southern hemisphere.
It deflects the wind to the right direction in the northern hemisphere.
Answer (c).
44. Chronologically arrange the following treaties/conventions signed between the Marathas and the British (starting with the earliest):
Treaty of Salbai
Treaty of Purandar
Convention of Wadgaon
Treaty of Surat
Select the correct answer using the code given below:
4-2-3-1
4-3-2-1
1-3-2-4
1-2-3-4
Answer (a).
45. Which of the following statements about the Sanyasi and Faqir disturbances/rebellions are correct?
Governor-General Warrent Hastings faced the persistent Sanyasi and Faqir disturbances in Bengal and Bihar.
There were a number of Shaivite Naga Sanyasis who formed into armed bands.
Manju Shah, who led bands into Bengal from 1771, was their prominent leader.
Select the correct answer using the code given below:
1 and 2 only
1, 2 and 3
2 and 3 only
1 and 3 only
Answer (b).
46. In 1943, young leaders in which one of the following districts of Maharashtra set up a parallel Government (prati sarkar) with volunteer corps (seva dals) and village units (tufan dals)?
Pune
Nasik
Nagpur
Satara
Answer (d).
47. Who founded the Central Hindu School at Benaras which was later developed into Benaras Hindu University?
Madan Mohan Malaviya
Annie Besant
Ishwar Chandra Vidyasagar
Madame H.P. Blavatsky
Answer (b)
48. Which one among the following is not a feature of centralization?
National unity
Uniformity
Prosperity
Liberty
Answer (d).
49. Which one of the following is not an objective of NITI Aayog?
It provides a critical direction and strategic input for development process.
It functions as a 'think tank' in providing key elements of policy.
It monitors and evaluates the implementation of the programmes.
It offers a platform for resolution of inter-state conflicts as 'provider of first and last resort'.
Answer (d).
50. Article 231 of the Constitution of India grants power to establish a common High Court for two or more states to
the Parliament
the Supreme Court
the President of India
the Union Cabinet
Answer (a).
51. Which one among the following motions cannot be made while introducing an ordinary Bill in the Parliament?
That the Bill be taken into consideration
That the Bill be circulated for the purpose of eliciting public opinion
That the Bill be referred to a Select Committee
That the Bill be referred to a Joint Committee of the House without the concurrence of the other House
Answer (d).
52. Which one among the following was eliminated by the 44th Amendment Act of the Parliament?
Right against Exploitation
Right to Constitional Remedies
Right to Property
Right to Education
Answer (c)
53. Identify the crop on the basis of the following characteristics:
It is a kharif crop.
Aus, Aman and Boro are its three different growing periods in an agricultural year.
About one-fourth of the total cropped area of India is under its cultivation.
Select the correct answer using the code given below:
Wheat
Rice
Pulses
Cotton
Answer (b).
54. Which one of the following is a type of igneous rock?
Marble
Halite
Granite
Shale
Answer (c).
55. Ozone layer, which absorbs the ultra-violet radiation, is found in which one of the following layers of the atmosphere?
Ionosphere
Troposphere
Mesosphere
Stratosphere
Answer (d).
56. Which one of the following statements about primary waves of earthquakes is not correct?
They are similar to sound waves.
They can travel only through solid materials.
They travel through gaseous, liquid and solid materials.
The move faster and are the first to arrive at the surface.
Answer (b).
57. Alluvial soils vary in nature from sandy loam to clay. They are generally
poor in potash and rich in phosphorus.
poor in both potash and phosphorus.
rich in both potash and phosphorus.
rich in potash and poor in phosphorus.
Answer (d).
58. Who among the following was popularly known as 'Lokahitwadi'?
Gopal Hari Deshmukh
Mahadev Govind Ranade
Gopal Krishna Gokhale
Jyotiba Phule
Answer (a).
59. Who among the following socialist activists persuaded Gandhiji not to restrict the salt march protest to men alone?
Kamaladevi Chattopadhyay
Sarojini Naidu
Matangini Hazra
Mithuben Petit
Answer (a).
60. Which one of the following painters was not associated with Humayun?
Mir Sayyid Ali
Maulana Dost Musawir
Maulana Yusuf
Bihzad
Answer (d).
61. Match List I with List II and selec the correct answer using the code given below the lists:
List I (Author)
List II (Poetical work)
A. Brindavan Das
1. Shivasankirttan
B. Krishnadas Kaviraj
2. Chandimangal
C. Mukundaram Chakravarti
3. Chaitanyacharitamrita
D. Ramesh Bhattacharya
4. Chaitanyamangal
Code:
A - 4; B - 2; C - 3; D - 1
A - 4; B - 3; C - 2; D - 1
A - 1; B - 3; C - 2; D - 4
A - 1; B - 2; C - 3; D - 4
Answer (b).
62. Which one of the following scholars of Akbar's court translated Bhaskaracharya's Lilavati into Persian?
Abul Fazl
Faizi
Fathullah Shirazi
Ataullah Rashidi
Answer (b).
63. Who among the following was the Chairman of the National Commission for Review of the Working of the Constitution (2000)?
Justice M.N. Venkatachaliah
Justice J.S. Verma
Justice Ranganath Mishra
Justice Y.K. Sabharwal
Answer (a).
64. M.M. Punchi Commission on Centre-State Relations has recommended the disposal of a bill reserved for the consideration of the Union Executive within
four months
six months
eigth months
five months
Answer (b).
65. Who among the following founded the Marathis newspaper 'Kesari'?
Lokmanya Tilak
Vallabhbhai Patel
Lala Lajpat Rai
Mahatma Gandhi
Answer (a).
66. Which mega public sector undertaking is designated with 'Navratna' status?
Indian Oil Corporation Limited
Gas Authority of India Limited
Bharat Petroleum Corporation Limited
Bharat Electronics Limited
Answer (d).
67. Which of the following statements with regard to the creation of a new state or alteration of boundaries of states is/are correct?
An amendment has to be moved in the Parliament under Article 368 of the Constitution of India.
Ratification by one half of the states is necessary after the amendment is made by the Parliament.
The legislation can be passed by a simple majority of both Houses of Parliament.
Select the correct answer using the code given below:
1 and 3
2 only
3 only
2 and 3 only
Answer (c).
68. Which one of the following is the largest linguistic group of India?
Sino-Tibetan
Austric
Indo-Aryan
Dravidian
Answer (c).
69. Which one of the following water bodies separates the Andaman and the Nicobar islands?
Gulf of Mannar
Ten Degree Channel
Eleven Degree Channel
Palk Strait
Answer (b).
70. Which one of the following longitudes is the standard meridian of India?
83o30' E
82o30' E
82o30' W
83o30' W
Answer (b).
71. Match List I with List II and selec the correct answer using the code given below the lists:
List I
List II
A. Cyclones
1. Western Australia
B. Hurricanes
2. South China Sea
C. Typhoons
3. Indian Ocean
D. Willy-willies
4. Atlantic Ocean
Code:
A - 3; B - 2; C - 4; D - 1
A - 3; B - 4; C - 2; D - 1
A - 1; B - 4; C - 2; D - 3
A - 1; B - 2; C - 4; D - 3
Answer (b).
72. Which one of the following is/are social security scheme(s)?
Atal Pension Yojana
Pradhan Mantri Jeevan Jyoti Bima Yojana
Pradhan Mantri Suraksha Bima Yojana
Select the correct answer using the code given below:
1 only
2 and 3 only
1,2 and 3
1 and 3 only
Answer (c).
73. Which one of the following units is not a part of All India Radio's Transcription and Programme Exchange Service?
Central Archives
Sound Archives
Advanced Research Unit
Transcription Unit
Answer (c).
74. Which of the following statements about the Panchayati Raj System are correct?
All seats in a Panchayat are filled by persons chosen by direct election.
The 'Gram Sabha' consists of persons registered in the village electoral rolls.
The Chairperson of a Panchayat is elected in accordance with a law passed by each state.
All states in India have a three-tier system of Panchayats.
Select the correct answer using the code given below:
1 and 4 only
1, 2 and 3 only
2 and 3 only
2, 3 and 4 only
Answer (b).
75. Which of the following statements is/are correct?
The elections to the Panchayat are conducted by the State Election Commission.
The State Election Commissioner is appointed by the Chief Election Commissioner of India.
The State Legislatures have the power to make laws on all matters relating to Panchayat elections.
Select the correct answer using the code given below:
2 only
1 and 2 only
1, 2 and 3
1 and 3 only
Answer (d).
76. Which one of the following is not a correct description of the Union Cabinet?
It is part of the Parliament.
It is responsible to the Parliament.
It is remains in power till it enjoys the confidence of the Parliament.
A person the outside the Parliament can never be appointed a member of the Cabinet.
Answer (X). Question cancelled by UPSC.
77. Which one of the following statements about the composition of the Parliament is not correct?
Representatives of the states in Rajya Sabha are elected directly by the people.
Representatives from Union Territories in Lok Sabha are chosen by direct elections.
Rajya Sabha has 12 nominated members.
Lok Sabha has seats reserved fro SCs and STs.
Answer (a).
78. Which among the following fundamental rights is/are available to non-citizens?
Freedom of speech
Protection against self-incrimination
Freedom of conscience
Non-discrimination in matters of employment
Select the correct answer using the code given below:
1, 2 and 3 only
1, 3 and 4 only
2 and 3 only
2 only
Answer (c).
79. Which one of the following statements about the Vice-President of India is not correct?
He is not eligible for re-election.
He must not be less than 35 years of age.
He is elected by members of an electoral college consisting of members of both Houses of Parliament.
His term of office is five years.
Answer (a).
80. A motion of no-confidence is moved against
an individual Minister.
the Council of Ministers.
the Prime Minister.
a political party.
Answer (b).
81. Which one of the is correct about 'Pinaka'?
It is a multi-barrel rocket system.
It is a type of battle tank.
It is an advanced submarine.
It is an indigenously developed drone system.
Answer (a).
82. Which one of the following is not a member of the Quad group of nations?
France
USA
Australia
Japan
Answer (a).
83. The first phase of Exercise Malabar, 2020 was conducted at
Port Blair
Mumbai
Visakhapatnam
Kochi
Answer (c).
84. Hollywood actor Sir Sean Connery, who died recently, was popularly known of the portrayal of the role
Rocky
Captain Jack Sparrow
Terminator
James Bond
Answer (d).
85. The Luhri Hydro-Electric Power Project is being constructed on the river
Satluj
Beas
Ravi
Chenab
Answer (a).
86. 'CARAT Bangladesh 2020' was a joint naval between Bangladesh and
India
USA
Japan
Thailand
Answer (b).
87. Peninsular Shield Force is a military arm of
Organization of Islamic Cooperation
Organization of the Petroleum Exporting Countries
Gulf Cooperation Council
Arab League
Answer (c).
88. Which one of the following ships was involved in 'Mission Sagar-II'?
INS Shakti
INS Vikramaditya
INS Kesari
INS Airawat
Answer (d).
89. In the year 2020 which one of the following tiger reserves of India was declared by UNESCO as a Biosphere Reserve?
Panna Tiger Reserve
Namdapha Tiger Reserve
Dudhwa Tiger Reserve
Pench Tiger Reserve
Answer (a).
90. The Kaleshwaram Lift Irrigation System, which was in the news recently, is constructed in
Kerala
Gujarat
Telangana
Maharashtra
Answer (c).
91. Cell wall is not present in cells of
Bacteria
Plants
Fungi
Humans
Answer (d).
92. A child receives a tall beautiful plant as a birthday gift from his father with a quiz. The father asked here how she would verify whether this tall plant was the progeny of both the tall parents or one tall and one short parent plant. She could verify this through
cross-pollination
self-pollination
tissue culture
negative propagation
Answer (b).
93. A student was doing an experiment on increasing the cell division among plants. She asked her supervisor to suggest the specific plant hormone for the same. Had you been her supervisor, which plant hormone would you suggest
Abscisic acid
Gibberellins
Cytokinin
Auxin
Answer (c).
94. Which cell organelles have their own DNA and Ribosomes?
Golgi body and Endoplasmic Reticulum
Mitochondria and Plastids
Lysosome and Golgi body
Vacuole and Plastids
Answer (b).
95. Osmosis is the process of movement of water molecules from its
higher concentration to its lower concentration through a cell wall.
lower concentration to its higher concentration through a fully permeable membrane.
higher concentration to its lower concentration through a fully permeable membrane.
higher concentration to its lower concentration through a semi-permeable membrane.
Answer (d).
96. Growing of two or more crops simultaneously on the same field in a definite pattern is known as
mixed cropping
inter cropping
mixed farming
hybrid farming
Answer (b).
97. When we heat lead nitrate [Pb(NO3)2] in a boiling tube, we observe the emission of brown fumes. Which one of the following is the brown gas?
NO
N2O2
NO3
NO2
Answer (d).
98. Which one of the following substances do silver articles react with, that makes the silver articles black?
Sulphur
Oxygen
Carbon dioxide
Phosphorus
Answer (a).
99. Which one of the following metals is kept immersed in Kerosene oil to protect it and to prevent accidental fire?
Calcium
Socium
Vanadium
Magnesium
Answer (b).
100. A solution contains 20 g of solute in 180 g of solvent. If the solvent is water, what is the concentration of the solution in terms of mass by mass percentage?
11.1%
22.2%
10%
20%
Answer (c).
101. Which one of the following elements is a non-metal but is lustrous?
Carbon
Silicon
Germanium
Iodine
Answer (d).
102. Which one of the following metals has both malleability and ductility properties?
Na
Au
Ce
Hg
Answer (b).
103. We are given three copper wires of different lengths and different areas of cross-section. Which one of the following would have highest resistivity
Copper wire of 50 cm length and 1 mm diameter
Copper wire of 25 cm length and 0.5 mm diameter
Copper wire of 10 cm length and 2.0 mm diameter
All the wires would have same resistivity
Answer (d).
104. Which of the following statements about 'fission' is correct?
It is related with the creation of new individuals by means of cell division in unicellular organism.
It is related with the transformation of heavier nuclei into smaller nuclei.
It is related with the creation of a heavier nuclei by means of combining two higher nuclei.
Select the correct answer using the code given below:
1 only
2 only
1 and 2 only
1 and 3 only
Answer (c).
105. Which one of the following is an electric conductor?
A plastic sheet
Distilled water
Human body
A wooden thin sheet
Answer (c).
106. A non-spherical shining spoon can generally be considered as a
Spherical mirror
Parabolic mirror
Plane mirror
Lens
Answer (b).
107. Who amongst the following is a pioneer in discovering the heating effect of electric current?
Isaac Newton
Galileo Galilei
James P. Joule
J.J. Thomson
Answer (c).
108. Which one of the following laws of electromagnetism does not give the direction of magnetic field?
Right-hand thumb rule
Fleming's left-hand rule
Fleming's right-hand rule
Faraday's law of electromagnetic induction
Answer (d).
109. An antibiotic is not useful against a virus whereas a vaccine is. Which one of the following is the most appropriate reason for this?
An antibiotic can break RNA only, whereas virus has DNA.
An antibiotic is a carbohydrate in its chemical nature, whereas a vaccine is a protein which works well to kill a virus.
Only a vaccine can break the genetic material of a virus.
A virus does not use biochemical pathways which can be blocked by and antibiotic. But a vaccine can boost an immune system to fight the virus.
Answer (d).
110. 'Sleeping sickness' is caused by
Trypanosoma
Leishmania
Plasmodium
Paramecium
Answer (a).
111. Which one among the following is a free living animal?
Liver fluke
Wuchereria
Plasmodium
Planaria
Answer (d).
112. Which one of the following is the structure of a cardiac muscle cell?
Cylindrical, Unbranched and Multinucleate
Spinal shaped, Unbranched and Uninucleate
Spinal shaped, Branched and Uninucleate
Cylindrical, Branched and Uninucleate
Answer (d).
113. Which one of the following naturally occurring acids is found in abundance in tomato?
Acetic acid
Citric acid
Oxalic acid
Tartaric acid
Answer (c).
114. Which one of the following is used in soda-acid fire extinguishers?
Sodium chloride
Sodium hydrogen carbonate
Calcium hydroxide
Acetic acid
Answer (b).
115. Which one of the following sodium compounds is used for softening hard water?
Na2CO3
NaHCO3
NaOH
Na2SO4
Answer (a).
116. Calcium oxide reacts vigorously with water to produce slaked lime whose solution is used for white-washing walls. This slaked lime reacts with component (A) in air to form a thin layer of component (B) to give a shiny finish. What are the components (A) and (B)?
A - O2; B - CaCO3
A - CO2; B - Ca(OH)2
A - O2; B - Ca(OH)2
A - CO2; B - CaCO3
Answer (d).
117. How many internal reflections of light take place in the formation of primary rainbow?
0
1
2
More than 2
Answer (b).
118. The direction of acceleration in uniform circular motion is along the
direction of motion
tangent to the circle at the point of observation
direction of velocity
direction perpendicular to velocity
Answer (d).
119. The weight of an object is due to
the net force acting on it.
the total of all forces acting on it irrespective of their directions.
the force that it exerts on the ground.
its inert property
Answer (c).
120. The size of particles being studies in 'nano-technology' is about