UPSC CAPF

41. A Barometer kept in an elevator reads 760 mm when the elevator is at r

A Barometer kept in an elevator reads 760 mm when the elevator is at rest. When the elevator moves in the upward direction with increasing speed, the reading of the Barometer will be:

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760 mm
> 760 mm
Zero
This question was previously asked in
UPSC CAPF – 2016
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When the elevator moves upward with increasing speed (i.e., it is accelerating upwards), the apparent weight of objects inside the elevator increases. A barometer measures the pressure exerted by the column of air above it. In the upward accelerating frame of reference, the effective acceleration of gravity is (g + a), where g is the standard acceleration due to gravity and a is the upward acceleration of the elevator. The pressure exerted by the air column is proportional to this effective gravity. Therefore, the air pressure measured by the barometer will be higher than the normal atmospheric pressure (760 mm Hg) measured when the elevator is at rest.
This question tests the understanding of apparent weight and pressure measurement in accelerating reference frames.
If the elevator were moving downwards with increasing speed (accelerating downwards), the apparent weight and measured pressure would decrease (reading < 760 mm). If the elevator were moving at a constant velocity (up or down), the acceleration would be zero, and the reading would remain 760 mm. If the elevator were falling freely (a = -g), the apparent weight and pressure would be zero.

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42. Which one of the following statements is correct ?

Which one of the following statements is correct ?

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Acceleration due to gravity decreases with the increase of altitude
Acceleration due to gravity increases with the increase of depth (assuming earth to be a sphere of uniform density)
Acceleration due to gravity decreases with the increase of latitude
Acceleration due to gravity is independent of the mass of the earth
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UPSC CAPF – 2016
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Statement A is correct. The acceleration due to gravity (g) on the surface of the Earth is given by the formula g = GM/R², where G is the gravitational constant, M is the mass of the Earth, and R is the distance from the center of the Earth. As altitude increases, R increases. Since g is inversely proportional to R², an increase in R leads to a decrease in g.
Understanding how the acceleration due to gravity varies with altitude, depth, latitude, and the mass of the celestial body is essential.
Statement B is incorrect: Acceleration due to gravity decreases with increasing depth inside the Earth. At depth d below the surface, g’ = g(1 – d/R), where R is the radius of the Earth. It becomes zero at the Earth’s center.
Statement C is incorrect: Acceleration due to gravity increases with increasing latitude, from the equator to the poles. This is due to the Earth’s equatorial bulge (closer to the center at poles) and the effect of Earth’s rotation (centrifugal force is maximum at the equator).
Statement D is incorrect: Acceleration due to gravity is directly proportional to the mass of the Earth (M).

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43. Which one of the following statements is not true ?

Which one of the following statements is not true ?

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The gravitational force of earth acting on a body of mass 1 kg is 9.8 newton
The force acting on an object of mass 5 kg moving with a uniform velocity of 10 m/s on a frictionless surface is zero
The SI unit of weight is kg
The momentum of a man having mass 100 kg walking with a uniform velocity of 2 m/s is 200 newton second
This question was previously asked in
UPSC CAPF – 2016
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Statement C is incorrect. Weight is the force exerted on a mass by gravity. The SI unit of force is the Newton (N). Kilogram (kg) is the SI unit of mass, which is a measure of the amount of matter in an object and is independent of gravity. Weight is measured in Newtons.
Distinguishing between mass and weight and knowing their respective SI units is a fundamental concept in physics.
Statement A is correct: The weight of a 1 kg mass on Earth, where the standard acceleration due to gravity (g) is approximately 9.8 m/s², is given by W = mg = 1 kg * 9.8 m/s² = 9.8 N.
Statement B is correct: If an object moves with uniform velocity, its acceleration is zero (a=0). According to Newton’s second law, the net force acting on the object is F = ma. If a=0, then F=0. On a frictionless surface, there are no opposing forces like friction.
Statement D is correct: Momentum (p) is calculated as mass (m) times velocity (v). p = 100 kg * 2 m/s = 200 kg⋅m/s. The unit kg⋅m/s is equivalent to Newton-second (N⋅s), as 1 N = 1 kg⋅m/s². So, the momentum is 200 N⋅s.

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44. A piece of stone tied to a string is made to revolve in a circular orb

A piece of stone tied to a string is made to revolve in a circular orbit of radius r with other end of the string as the centre. If the string breaks, the stone will :

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move away from the centre.
move towards the centre.
move along a tangent.
stop.
This question was previously asked in
UPSC CAPF – 2016
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When an object is revolving in a circular orbit, its velocity at any point is directed tangentially to the circle at that point. The string provides the centripetal force required to keep the object moving in a circular path, constantly changing its direction. If the string breaks, this centripetal force is removed. According to Newton’s first law of motion (the law of inertia), an object in motion will continue in a straight line with constant speed unless acted upon by an external force. Therefore, the stone will move in a straight line along the direction of its instantaneous velocity at the moment the string breaks, which is tangential to the circular orbit.
Understanding inertia and tangential velocity in circular motion is key to predicting the motion of an object when the centripetal force is removed.
This phenomenon demonstrates Newton’s first law and the nature of velocity in circular motion. The stone does not move away from the center (that would imply a radially outward force, which doesn’t exist upon breaking), nor does it move towards the center (as the inward centripetal force is gone), nor does it stop (unless there is friction or air resistance acting).

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45. Consider the following physical quantities : Energy, power, pressure,

Consider the following physical quantities :
Energy, power, pressure, impulse, temperature, gravitational potential
Which of the above is / are the vector quantity/quantities ?

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Impulse only
Impulse and pressure only
Impulse, temperature and pressure
Gravitational potential
This question was previously asked in
UPSC CAPF – 2016
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Among the given physical quantities, only Impulse is a vector quantity. A vector quantity has both magnitude and direction. Impulse is defined as the change in momentum of an object, and momentum (mass × velocity) is a vector quantity. Impulse is also equal to the force multiplied by the time interval over which the force acts (when force is constant), and force is a vector.
Identifying whether a physical quantity is a vector or a scalar is a basic concept in physics.
Energy, power, pressure, temperature, and gravitational potential are all scalar quantities. Scalar quantities are completely described by their magnitude alone. While pressure involves force (a vector) acting over an area (direction can be associated with area normal), pressure itself at a point is a scalar property of the fluid or material. Gravitational potential is potential energy per unit mass, and potential energy is a scalar.

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

Which one of the following statements is not correct ?

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Graphite is a non-metal
Graphite is an allotrope of carbon
Graphite is a conductor of electricity
Graphite has a tetrahedral structure
This question was previously asked in
UPSC CAPF – 2016
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Statement D is incorrect. Graphite has a layered structure where carbon atoms are arranged in hexagonal rings. Each carbon atom is covalently bonded to three other carbon atoms within the same layer. These layers are held together by weak van der Waals forces. A tetrahedral structure is characteristic of diamond, another allotrope of carbon, where each carbon atom is bonded to four other carbon atoms in a three-dimensional network.
Distinguishing between the structures of different allotropes of carbon like graphite and diamond is fundamental in chemistry and materials science.
Statement A is correct: Graphite is an allotrope of carbon, which is a non-metal element.
Statement B is correct: Graphite is one of the naturally occurring allotropes of carbon.
Statement C is correct: Graphite is a good conductor of electricity due to the presence of delocalized electrons within its layered structure, which can move freely along the layers.

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

Which one of the following statements is not correct ?

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”Bleaching
” option2=”Bleaching powder acts as a reducing agent in many chemical industries” option3=”Bleaching powder is also known as chlorinated lime” option4=”Bleaching powder is used for disinfecting drinking water” correct=”option2″]

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This question was previously asked in
UPSC CAPF – 2016
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Statement B is incorrect. Bleaching powder (Calcium oxychloride, CaOCl₂) is a strong oxidizing agent due to the presence of available chlorine. It acts as an oxidizing agent in bleaching processes and disinfection, not a reducing agent. Reducing agents donate electrons or hydrogen atoms, while oxidizing agents accept electrons or remove hydrogen atoms. Bleaching powder facilitates oxidation reactions.
Understanding the chemical properties of common substances like bleaching powder, specifically its role as an oxidizing agent, is important.
Statement A is correct: Bleaching powder is prepared by passing chlorine gas over dry slaked lime [Ca(OH)₂]. The reaction is Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O.
Statement C is correct: Bleaching powder is also known as chlorinated lime or calcium hypochlorite.
Statement D is correct: Bleaching powder is widely used for disinfecting drinking water, swimming pools, and sanitation purposes because its oxidizing action kills bacteria and other microorganisms.

48. Which one of the following is not an industrial corridor as per the po

Which one of the following is not an industrial corridor as per the policy initiatives ?

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Amritsar - Kolkata
Delhi - Mumbai
Kolkata - Guwahati
Chennai - Bengaluru
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UPSC CAPF – 2016
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As per the policy initiatives of the Indian government regarding industrial corridors, the Amritsar – Kolkata, Delhi – Mumbai, and Chennai – Bengaluru corridors are designated as major industrial corridors aimed at facilitating industrial development and connectivity. The Kolkata – Guwahati route, while important for connectivity, is not typically listed as one of the established major industrial corridors in the same context as the others.
Identifying the officially recognized and planned industrial corridors in India is crucial for understanding the country’s infrastructure and industrial development strategy.
Major industrial corridors in India include the Delhi-Mumbai Industrial Corridor (DMIC), Amritsar-Kolkata Industrial Corridor (AKIC), Chennai-Bengaluru Industrial Corridor (CBIC), East Coast Economic Corridor (ECEC) which includes the Vizag-Chennai Industrial Corridor, and the Bengaluru-Mumbai Economic Corridor (BMEC). These corridors leverage dedicated freight corridors and highways to create manufacturing hubs and smart cities.

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49. During 2014-2015, in which one of the following industrial sectors, th

During 2014-2015, in which one of the following industrial sectors, the FDI equity inflow was maximum ?

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Telecommunications
Services (Financial, Banking and Insurance, Non-Financial / Business, R & D etc.)
Drugs and Pharmaceuticals
Hotel and Tourism
This question was previously asked in
UPSC CAPF – 2016
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Data for the fiscal year 2014-2015 on FDI equity inflows into India shows that the Services sector received the maximum amount of foreign direct investment during this period.
Understanding the distribution of FDI inflows across different sectors of the Indian economy is important for assessing investment patterns and economic priorities.
The Services sector typically includes a wide range of activities such as financial services, banking, insurance, business services (including R&D, consulting, and software), communication services, and other miscellaneous services. This sector has consistently been a major recipient of FDI in India over the years. The data cited is based on official statistics released by the Department for Promotion of Industry and Internal Trade (DPIIT), Government of India.

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50. Arrange the following substances in their order of increasing hardness

Arrange the following substances in their order of increasing hardness :

  1. Gypsum
  2. Topaz
  3. Fluorite
  4. Feldspar

Select the correct answer using the code given below :

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4-3-2-1
1-3-4-2
3-4-2-1
1-4-3-2
This question was previously asked in
UPSC CAPF – 2016
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The correct answer is B) 1-3-4-2.
– The hardness of minerals is commonly measured using the Mohs Hardness Scale, which ranks minerals from 1 (softest) to 10 (hardest) based on their ability to scratch one another.
– The Mohs scale values for the given substances are:
– Gypsum: Mohs Hardness = 2
– Topaz: Mohs Hardness = 8
– Fluorite: Mohs Hardness = 4
– Feldspar (usually Orthoclase): Mohs Hardness = 6
– Arranging these substances in order of increasing hardness (from softest to hardest):
1. Gypsum (2)
2. Fluorite (4)
3. Feldspar (6)
4. Topaz (8)
– The correct order using the list numbers is 1-3-4-2.
The full Mohs scale is: 1. Talc, 2. Gypsum, 3. Calcite, 4. Fluorite, 5. Apatite, 6. Feldspar, 7. Quartz, 8. Topaz, 9. Corundum, 10. Diamond. Each mineral on the scale can scratch the ones below it. For example, Fluorite (4) can scratch Gypsum (2) and Calcite (3), but cannot scratch Apatite (5) or Feldspar (6).

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