2016 Archives

231. Which of the following statements with regard to coverage rate of Aadh

Which of the following statements with regard to coverage rate of Aadhar cards during 2015 is/are correct ?

1. The coverage rate of Aadhar cards in western India is quite high and it is above 90 per cent in Gujarat
2. The coverage rate of Aadhar cards is the highest in southern India and it is almost 100 per cent in the states of Telangana and Andhra Pradesh
3. The penetration of Aadhar cards has been very low in north-eastern part of India and it is the lowest in Assam and Meghalaya

Select the correct answer using the code given below :

[amp_mcq option1=”2 only” option2=”1 and 3 only” option3=”2 and 3 only” option4=”1, 2 and 3″ correct=”option4″]

This question was previously asked in

UPSC NDA-2 – 2016

The correct answer is D) 1, 2 and 3. Based on the Aadhar enrolment data and trends reported around 2015-16:
1. The coverage rate in Western India, including Gujarat, was indeed quite high, generally above 90% for the eligible population.
2. Southern states consistently showed high coverage rates. Telangana and Andhra Pradesh were among the leading states with very high enrolment figures, often cited as approaching universal coverage for the eligible population by 2015-16.
3. States in the North-Eastern part of India, particularly Assam and Meghalaya, faced significant challenges and delays in Aadhar enrolment due to various factors, resulting in very low coverage rates compared to the national average and other states during this period.

– Aadhar enrolment progress varied significantly across Indian states.
– States in the South and West generally achieved higher coverage rates earlier.
– States in the North-East, especially Assam and Meghalaya, had considerably lower coverage due to unique challenges.

– By the end of 2015 and early 2016, the Aadhar project had achieved substantial coverage nationally, but regional disparities existed.
– The low coverage in Assam was partly linked to the ongoing process of updating the National Register of Citizens (NRC).
– These trends were widely reported in government documents and media coverage regarding the Aadhar rollout.

232. If one mixes up ashes with animal fat, the substance received in the c

If one mixes up ashes with animal fat, the substance received in the crude form is called

[amp_mcq option1=”Pheromone” option2=”Soap” option3=”Cement” option4=”Concrete” correct=”option2″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is B) Soap. Historically, soap was produced by boiling animal fat with lye, which is an alkaline solution obtained from leaching ashes (often wood ashes containing potassium carbonate, which reacts with water to form potassium hydroxide, or using lime to convert sodium carbonate from plant ashes into sodium hydroxide). The process, called saponification, involves the hydrolysis of fats or oils (triglycerides) by an alkali to produce glycerol and fatty acid salts, which are soap. Mixing ashes (source of alkali) with animal fat is a crude method of making soap.

– Soap is made through saponification, a reaction between fats/oils and an alkali.
– Animal fat provides triglycerides.
– Ashes, particularly from wood, can provide alkali (potassium carbonate/hydroxide) when mixed with water.
– This historical process yields crude soap.

– Pheromones are chemical signals released by organisms.
– Cement is a binder substance used in construction.
– Concrete is a composite material made from cement, aggregate, water, and sometimes admixtures.

233. Emulsion is known as a

Emulsion is known as a

[amp_mcq option1=”colloidal solution of substances having different physical states” option2=”true solution” option3=”distillation mixture for making alcohols” option4=”colloidal solution of two liquids” correct=”option4″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is D) colloidal solution of two liquids. An emulsion is a specific type of colloid where one liquid is dispersed throughout another liquid in the form of tiny droplets. The two liquids are typically immiscible or poorly miscible.

– Emulsions are colloidal systems.
– The dispersed phase and the dispersion medium are both liquids.
– Examples include milk (fat droplets dispersed in water) and mayonnaise (oil dispersed in vinegar).

– Colloidal solutions can involve different physical states (e.g., solid in gas for smoke, liquid in gas for fog), but an emulsion is specifically liquid in liquid.
– A true solution is a homogeneous mixture where the solute is dissolved at the molecular or ionic level, unlike a colloid which has larger dispersed particles.
– Distillation is a separation technique, not a type of solution or mixture in this context.

234. The setting time of cement is lowered by adding

The setting time of cement is lowered by adding

[amp_mcq option1=”oxides of aluminium” option2=”gypsum” option3=”oxides of magnesium” option4=”silica” correct=”option1″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is A) oxides of aluminium. The question asks what is added to lower the setting time of cement, which means making it set faster. Gypsum (option B) is added to *increase* the setting time (retard setting). While standard accelerators are typically calcium chloride or alkali aluminates, reactive forms of aluminium oxides or phases rich in alumina like Calcium Aluminate Cements (CAC) or specific additives containing activated alumina can act as accelerators, causing rapid setting. Therefore, among the given options, oxides of aluminium (in a suitable form or context as present in cement phases like C₃A) are the most plausible candidates for contributing to or accelerating the setting process compared to the other options which are either retarders (gypsum) or primary components/cause of expansion (magnesium oxide).

– Setting time refers to the time required for cement paste to lose its plasticity.
– Additives are used to control setting time: accelerators decrease setting time, retarders increase it.
– Gypsum is a common retarder, preventing flash set by reacting with C₃A.
– Oxides of aluminium are present in cement clinker primarily as tricalcium aluminate (C₃A), which hydrates rapidly and contributes to early setting. Certain forms of reactive alumina can act as accelerators.

– Calcium chloride (CaCl₂) is a very common and effective accelerator used in cement.
– Oxides of magnesium (MgO), if present in excess in portland cement, can cause delayed expansion and soundness issues, not primarily affecting initial setting time in a controlled manner.
– Silica (SiO₂) is a main component of cement (silicates C₃S and C₂S), which are responsible for strength development, but adding pure silica is not a method to control setting time.
– The phrasing “lowered by adding” implies acceleration. While gypsum is a crucial additive related to setting time, its effect is the opposite (increasing/retarding). This points towards A as the intended answer, assuming a context where an aluminium oxide based additive is used for acceleration.

235. Two balls, A and B, are thrown simultaneously. A vertically upward wit

Two balls, A and B, are thrown simultaneously. A vertically upward with a speed of 20 m/s from the ground and B vertically downward from a height of 40 m with the same speed and along the same line of motion. At what points do the two balls collide by taking acceleration due to gravity as 9.8 m/s²?

[amp_mcq option1=”The balls will collide after 3s at a height of 30·2 m from the ground” option2=”The balls will collide after 2s at a height of 20·1 m from the ground” option3=”The balls will collide after 1s at a height of 15·1 m from the ground” option4=”The balls will collide after 5s at a height of 20 m from the ground” correct=”option3″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is C) The balls will collide after 1s at a height of 15·1 m from the ground.
Let the origin be the ground level, with the upward direction as positive.
For ball A (thrown upward from ground):
Initial position, y₀_A = 0
Initial velocity, u_A = +20 m/s
Equation of motion: y_A(t) = y₀_A + u_A*t – (1/2)gt² = 0 + 20t – (1/2)(9.8)t² = 20t – 4.9t²

For ball B (thrown downward from 40 m):
Initial position, y₀_B = 40 m
Initial velocity, u_B = -20 m/s
Equation of motion: y_B(t) = y₀_B + u_B*t – (1/2)gt² = 40 – 20t – (1/2)(9.8)t² = 40 – 20t – 4.9t²

Collision occurs when y_A(t) = y_B(t):
20t – 4.9t² = 40 – 20t – 4.9t²
Add 20t and 4.9t² to both sides:
40t = 40
t = 1 second

Substitute t = 1s into either equation to find the height:
y_A(1) = 20(1) – 4.9(1)² = 20 – 4.9 = 15.1 m
y_B(1) = 40 – 20(1) – 4.9(1)² = 40 – 20 – 4.9 = 15.1 m

The balls collide after 1 second at a height of 15.1 m from the ground.

– Use equations of motion under constant acceleration (gravity).
– Define a consistent coordinate system (origin and positive direction).
– Set the positions of the two objects equal to find the time of collision.
– Use the time of collision to find the position (height) of collision.

– The acceleration due to gravity (g) is taken as 9.8 m/s² downwards.
– The relative velocity approach could also be used for the time of collision: v_rel = v_A – v_B. Initial relative velocity = 20 – (-20) = 40 m/s. The relative acceleration is g – g = 0. The initial separation is 40m. Time to collide = separation / relative velocity = 40m / 40m/s = 1s. This confirms the time calculation.

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

Which one of the following statements is not correct ?

[amp_mcq option1=”The SI unit of charge is ampere-second” option2=”Debye is the unit of dipole moment” option3=”Resistivity of a wire of length l and area of cross-section a depends upon both l and a” option4=”The kinetic energy of an electron of mass m kg and charge e coulomb, when accelerated through a potential difference of V volt, is eV joule” correct=”option3″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is C) Resistivity of a wire of length l and area of cross-section a depends upon both l and a. This statement is incorrect. Resistivity ($\rho$) is an intrinsic property of the material of the wire and depends only on the material composition and temperature, not on its dimensions (length ‘l’ or area of cross-section ‘a’). The resistance (R) of the wire depends on resistivity, length, and area (R = $\rho$ * l/a).

– Resistivity is a material property.
– Resistance depends on material, length, and area.
– Charge unit is Coulomb (C) or Ampere-second (A·s).
– Debye is a unit for electric dipole moment.
– Kinetic energy gained by a charge ‘e’ accelerated by potential ‘V’ is eV.

– Statement A is correct: The SI unit of charge is Coulomb (C), and 1 Coulomb = 1 Ampere * 1 second (C = A·s).
– Statement B is correct: Debye (D) is a common unit used to measure the electric dipole moment of molecules.
– Statement D is correct: When a charge ‘e’ is accelerated through a potential difference ‘V’, the work done on the charge is W = V * e. By the work-energy theorem, this work is converted into kinetic energy, so Kinetic Energy = eV.

237. The property of electric current which is applicable in the fuse wire

The property of electric current which is applicable in the fuse wire is

[amp_mcq option1=”chemical effect of current” option2=”magnetic effect of current” option3=”heating effect of current” option4=”optical property of current” correct=”option3″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is C) heating effect of current. A fuse wire is designed to melt and break the circuit when the current flowing through it exceeds a certain limit. This melting is caused by the heat generated due to the resistance of the wire when current passes through it, which is known as the heating effect of electric current (Joule’s Law).

– Fuse wire protects electrical circuits from overcurrents.
– Its operation relies on melting due to excessive heat.
– The heat generated is proportional to the square of the current and the resistance of the wire (H = I²Rt).

– Chemical effect of current is related to electrolysis.
– Magnetic effect of current is used in devices like motors, relays, and electromagnets.
– Optical property of current is not a standard term; effects like light emission (LEDs) are related to current flow but not the principle behind a fuse.

238. As per census 2011, which one of the following states has the highest

As per census 2011, which one of the following states has the highest number of inhabited villages ?

[amp_mcq option1=”Uttar Pradesh” option2=”Odisha” option3=”Rajasthan” option4=”Maharashtra” correct=”option1″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is A) Uttar Pradesh. As per the Census 2011 data, Uttar Pradesh had the highest number of inhabited villages among all states in India.

– Census 2011 is the source for the number of inhabited villages per state.
– Uttar Pradesh, being the most populous state, also has the largest number of administrative units like villages.

– The total number of inhabited villages in India according to Census 2011 was 597,608.
– Uttar Pradesh accounted for over 107,000 of these inhabited villages.
– States like Bihar, Maharashtra, and West Bengal also have a high number of inhabited villages, but less than Uttar Pradesh. Odisha and Rajasthan have fewer.

239. Which one of the following sectors is the largest contributor to carbo

Which one of the following sectors is the largest contributor to carbon dioxide emissions from fuel consumption in India ?

[amp_mcq option1=”Electricity and heat production” option2=”Transport” option3=”Manufacturing industries and constructions” option4=”Others” correct=”option1″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is Electricity and heat production.

In India, the combustion of fossil fuels, primarily coal, for electricity generation is the largest single source of carbon dioxide emissions.

India relies heavily on thermal power plants, mainly coal-based, to meet its energy demands. Burning coal for power generation releases significant amounts of CO2, making the electricity and heat production sector the largest contributor to India’s CO2 emissions from fuel combustion. While other sectors like transport and manufacturing also contribute substantially, the power sector’s emissions are significantly higher due to the large scale of fossil fuel (especially coal) consumption.

240. The world’s largest biomass cookstove system for cooking in community

The world’s largest biomass cookstove system for cooking in community kitchen has been installed at

[amp_mcq option1=”Tirupati” option2=”Amritsar” option3=”Shirdi” option4=”Udupi” correct=”option3″]

This question was previously asked in

UPSC NDA-2 – 2016

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The correct answer is Shirdi.

A large biomass cookstove system for community cooking has been installed at the Shri Saibaba Sansthan Trust (Shirdi) in Maharashtra, recognized as one of the world’s largest.

The community kitchen (Langar/Prasadalaya) at the famous Saibaba temple in Shirdi serves thousands of devotees daily. To manage the massive cooking requirements, a large-scale solar steam cooking system supplemented by a biomass gasifier-based system was installed, often cited as one of the largest of its kind globally, particularly for biomass cookstoves in a community kitchen setting. While other places like Tirupati and Amritsar (Golden Temple, known for its massive Langar) also have large community kitchens, the biomass cookstove system at Shirdi is particularly noted for its scale and technology in this context.