UPSC NDA-1 Archives

41. Which one of the following statements about gravitational force is NOT

Which one of the following statements about gravitational force is NOT correct?

It is experienced by all bodies in the universe

It is a dominant force between celestial bodies

It is a negligible force for atoms

It is same for all pairs of bodies in our universe

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

According to Newton’s Law of Universal Gravitation, the gravitational force (F) between two objects with masses m₁ and m₂ separated by a distance r is given by F = G * (m₁*m₂)/r², where G is the gravitational constant. This formula shows that the gravitational force depends on the masses of the two bodies and the distance between their centers. Therefore, the gravitational force is *not* the same for all pairs of bodies in the universe. It varies depending on their masses and separation.

– Gravitational force is a universal force acting between any two objects with mass.
– The magnitude of the gravitational force depends on the product of the masses and the square of the distance between them.
– Gravity is the weakest of the fundamental forces but is dominant on large scales due to the large masses of celestial bodies.

Statements A, B, and C are correct. Gravity acts on all bodies with mass. It is the dominant force holding together planets, stars, and galaxies. At the atomic and subatomic levels, the masses are extremely small, making the gravitational force between them negligible compared to electromagnetic and nuclear forces.

Join Our Telegram Channel

42. Which one of the following is the value of 1 kWh of energy converted i

Which one of the following is the value of 1 kWh of energy converted into joules ?

1.8 × 10⁶ J

3.6 × 10⁶ J

6.0 × 10⁶ J

7.2 × 10⁶ J

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

1 kWh is a unit of energy commonly used for electrical energy consumption. It stands for kilowatt-hour. To convert it to joules (the SI unit of energy), we need to convert the power unit (kW) to watts (W) and the time unit (hour) to seconds (s).
1 kilowatt (kW) = 1000 Watts (W)
1 hour (h) = 60 minutes * 60 seconds = 3600 seconds (s)
Energy (E) = Power (P) × Time (t)
1 kWh = 1 kW × 1 h = (1000 W) × (3600 s) = 3,600,000 Ws
Since 1 Watt-second (Ws) is equal to 1 Joule (J),
1 kWh = 3,600,000 J = 3.6 × 10⁶ J.

– kWh is a unit of energy, not power.
– 1 Watt = 1 Joule per second (1 W = 1 J/s).
– 1 kilowatt = 1000 Watts.
– 1 hour = 3600 seconds.

Joules are the standard SI unit for energy. kWh is a practical unit for measuring large amounts of energy, like electricity consumption in households or industries. Power is the rate at which energy is consumed or transferred; 1 Watt is 1 Joule per second.

Join Our Telegram Channel

43. Which one of the following has maximum inertia ?

Which one of the following has maximum inertia ?

An atom

A molecule

A one-rupee coin

A cricket ball

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

Inertia is the property of an object that resists changes in its state of motion (either rest or uniform velocity in a straight line). Inertia is directly proportional to the mass of an object. The greater the mass, the greater its inertia. Comparing the given options, a cricket ball has significantly more mass than a one-rupee coin, a molecule, or an atom. Therefore, the cricket ball has the maximum inertia among the given options.

– Inertia is the resistance of an object to changes in its state of motion.
– Inertia is a scalar quantity.
– Inertia is directly proportional to mass.

Mass is the quantitative measure of inertia. For example, it is much harder to start moving a heavy object or stop a heavy object already in motion compared to a light object, because the heavy object has more inertia.

Join Our Telegram Channel

44. What is the net force experienced by a bar magnet placed in a uniform

What is the net force experienced by a bar magnet placed in a uniform magnetic field?

Zero

Depends upon length of the magnet

Never zero

Depends upon temperature

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

A bar magnet has two poles, a North pole and a South pole. When placed in a uniform magnetic field, the field exerts a force on each pole. The force on the North pole is in the direction of the magnetic field, and the force on the South pole is equal in magnitude but in the opposite direction to the magnetic field. Since the field is uniform, the forces on the two poles are equal and opposite, resulting in a net force of zero on the magnet. Although there is no net force, there is usually a torque which tends to align the magnetic dipole moment of the bar magnet with the direction of the uniform magnetic field.

– A bar magnet is a magnetic dipole.
– In a uniform magnetic field, the force on the North pole is equal and opposite to the force on the South pole.
– The net force is the vector sum of the forces on the individual poles.

If the magnetic field were non-uniform, the forces on the two poles would not be equal and opposite, and there would be a non-zero net force on the magnet, in addition to the torque. This is why magnets are attracted to or repelled from other magnets or ferromagnetic materials where the field is non-uniform.

Join Our Telegram Channel

45. An object is moving with uniform acceleration a. Its initial velocity

An object is moving with uniform acceleration a. Its initial velocity is u and after time t its velocity is v. The equation of its motion is v = u + at. The velocity (along y-axis) time (along x-axis) graph shall be a straight line

Join Our Telegram Channel

passing through origin

with x-intercept u

with y-intercept u

with slope u

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

The given equation of motion is v = u + at. We are asked about the velocity (v) vs. time (t) graph. This equation is in the form of a linear equation, y = mx + c, where v corresponds to y, t corresponds to x, ‘a’ (uniform acceleration) is the slope (m), and ‘u’ (initial velocity) is the y-intercept (c). The y-intercept is the value of y when x=0. In this case, it is the value of velocity (v) when time (t) is zero, which is the initial velocity ‘u’. Therefore, the graph is a straight line with a y-intercept equal to u.

– The equation v = u + at is a linear relationship between velocity (v) and time (t) for uniform acceleration.
– In a linear equation y = mx + c, ‘c’ is the y-intercept and ‘m’ is the slope.
– On a velocity-time graph, the y-axis represents velocity and the x-axis represents time.

The slope of the velocity-time graph represents the acceleration. Since the acceleration ‘a’ is uniform (constant), the graph is a straight line. The graph passes through the origin only if the initial velocity u is zero. The x-intercept would be the time when velocity is zero, which is t = -u/a (if applicable and physically meaningful).

46. If an object moves with constant velocity then which one of the follow

If an object moves with constant velocity then which one of the following statements is NOT correct ?

Its motion is along a straight line

Its speed changes with time

Its acceleration is zero

Its displacement increases linearly with time

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

If an object moves with constant velocity, it means that both its speed and its direction of motion are constant. Therefore, its speed does *not* change with time. Statement B says its speed changes with time, which contradicts the definition of constant velocity, making it the incorrect statement.

– Constant velocity implies constant speed and constant direction.
– Acceleration is the rate of change of velocity.
– Displacement is the change in position.

– Motion along a straight line means constant direction. Constant velocity guarantees this.
– Zero acceleration means no change in velocity. Constant velocity means zero acceleration.
– If velocity (v) is constant, displacement (s) is given by s = v*t. For a constant v, s increases linearly with time t.

Join Our Telegram Channel

47. If T is the time period of an oscillating pendulum, which one of the f

If T is the time period of an oscillating pendulum, which one of the following statements is NOT correct ?

The motion repeats after time T only once

T is the least time after which motion repeats itself

The motion repeats itself after nT, where n is a positive integer

T remains the same only for small angular displacements

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

The time period (T) of an oscillating pendulum is defined as the smallest time interval after which the motion repeats itself. While the motion does repeat after time T, it also repeats after any integer multiple of T (2T, 3T, 4T, etc.). Therefore, the statement that the motion repeats after time T “only once” is incorrect. The oscillation continues to repeat after every interval of T.

– A periodic motion repeats itself after a fixed interval of time called the time period.
– The time period T is the *minimum* time for the motion to repeat.
– The motion repeats after nT, where n is a positive integer.

For a simple pendulum undergoing Simple Harmonic Motion (SHM) at small angles, the time period is given by T = 2π√(L/g), where L is the length of the pendulum and g is the acceleration due to gravity. For larger angles, the period is slightly longer and depends on the amplitude, making the statement D (T remains the same only for small angular displacements) correct for the conditions under which the simple pendulum formula is typically derived.

Join Our Telegram Channel

48. Which one of the following statements is correct ?

Which one of the following statements is correct ?

Join Our Telegram Channel

Any energy transfer that does not involve temperature difference in some way is not heat

Any energy transfer always requires a temperature difference

On heating the length and volume of the object remain exactly the same

Whenever there is a temperature difference, heat is the only way of energy transfer

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

This question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer.

Let’s analyze each statement:
A) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn’t involve a temperature difference is not heat.
B) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference.
C) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0°C and 4°C).
D) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.

The First Law of Thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system ($\Delta U = Q – W$). This equation clearly distinguishes between heat (Q) and work (W) as two primary modes of energy transfer. Heat is driven by temperature difference, while work is driven by forces and displacement.

49. Which one of the following is NOT an objective of the National Civil A

Which one of the following is NOT an objective of the National Civil Aviation Policy 2016 ?

Establish an integrated eco-system which will lead to significant growth of civil aviation sector

To promote tourism, increase emp loyment and lead to a balanced regional growth

Ensure safety, security and sustaina bility of all sectors through the use of technology

Enhance regional connectivity through fiscal support and infra structure development

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2017

Download PDF Attempt Online

The National Civil Aviation Policy (NCAP) 2016 was a landmark policy aimed at providing a strategic direction for the growth of the Indian civil aviation sector. It outlined several objectives to achieve this goal.

Let’s examine the given statements against the known objectives of NCAP 2016:
A) Establish an integrated eco-system which will lead to significant growth of civil aviation sector: This is a primary overarching objective of the policy.
B) To promote tourism, increase employment and lead to a balanced regional growth: These were explicitly stated socio-economic objectives expected as outcomes of the policy, particularly through enhanced connectivity.
C) Ensure safety, security and sustaina bility of all sectors through the use of technology: While safety, security, and sustainability are fundamental principles and objectives in aviation, and technology is crucial for achieving them, stating that these are ensured *solely* or primarily “through the use of technology” might not be the direct and complete representation of the policy’s objective. The policy aims to ensure safety, security, and sustainability through various measures, including regulatory oversight, infrastructure development, training, and technological adoption, not just the latter. The objective is the outcome, not specifically the method tied only to technology.
D) Enhance regional connectivity through fiscal support and infra structure development: Enhancing regional connectivity (e.g., UDAN scheme) was a key focus, supported by Viability Gap Funding (VGF) (fiscal support) and infrastructure upgrades at regional airports. This is a clear objective.
Comparing the options, statement C adds a limiting condition (“through the use of technology”) to a fundamental objective (safety, security, sustainability) that is achieved through multiple means, making it potentially not the exact stated objective or less accurate than the others. The other options are direct reflections of the policy’s stated aims.

NCAP 2016 introduced several key initiatives like the Regional Connectivity Scheme (UDAN), rationalized the 5/20 rule for international operations, and provided a framework for various sub-sectors like ground handling, MRO, cargo, and helicopters.

Join Our Telegram Channel

50. Arrange the following countries in ascending order on the basis of the

Arrange the following countries in ascending order on the basis of the total medals earned by them in Rio Olympic 2016 :

United States
China
Great Britain
Russia

Select the correct answer using the code given below :

Join Our Telegram Channel

1, 2, 3, 4

1, 3, 2, 4

4, 3, 2, 1

4, 3, 1, 2

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2017

Download PDF Attempt Online

The question asks to arrange the given countries based on the total medals earned in the Rio Olympic 2016 in ascending order (from fewest medals to most medals).

The total medal counts for the specified countries in the Rio 2016 Summer Olympics were:
1. United States: 121 medals
2. China: 70 medals
3. Great Britain: 67 medals
4. Russia: 56 medals
Arranging these countries in ascending order of total medals:
Russia (56) < Great Britain (67) < China (70) < United States (121) The corresponding numbers from the list are: 4 (Russia), 3 (Great Britain), 2 (China), 1 (United States). So the ascending order is 4, 3, 2, 1.

The United States traditionally tops the medal tally in the Summer Olympics. Great Britain had a very successful performance in Rio, finishing second in the gold medal count and second to the US in total medals among these four countries. Russia’s participation was affected by doping controversies, leading to exclusion of some athletes.