In respect of the difference of the gravitational force from electric and magnetic forces, which one of the following statements is true ?

1. Introduction to Non-contact Forces (basic)

In our daily lives, we usually associate force with physical touch—pushing a door, lifting a suitcase, or kicking a football. These are known as contact forces because they require physical interaction between objects. However, nature also operates through forces that act across empty space without any physical connection. These are called non-contact forces. As explored in Science, Class VIII NCERT, Chapter 5, p.69, these forces allow objects to exert a push or a pull on each other even when they are separated by a distance.

There are three primary types of non-contact forces you should master: Magnetic, Electrostatic, and Gravitational forces. For instance, a magnet can move a compass needle without touching it, illustrating magnetic force Science, Class VIII NCERT, Chapter 5, p.77. Similarly, if you rub a balloon against woolen cloth, it can attract strands of your hair through electrostatic force. The most omnipresent example, however, is gravitational force, which pulls a falling fruit toward the Earth or keeps the planets in their orbits Science, Class VIII NCERT, Chapter 5, p.77.

While all these forces act at a distance, they have a fundamental difference in their "personality." Both magnetic and electrostatic forces can be attractive or repulsive (like poles/charges repel, while opposites attract). In contrast, gravity is exclusively attractive; it always pulls objects together and never pushes them away. Furthermore, while gravity is technically the weakest of these forces, it dominates the universe because it is long-range and always adds up as mass increases.

Force Type	Nature of Interaction	Example
Magnetic	Attractive or Repulsive	Compass needle pointing North
Electrostatic	Attractive or Repulsive	Rubbed comb attracting paper bits
Gravitational	Always Attractive	An apple falling from a tree

Sources: Science, Class VIII NCERT (2025), Chapter 5: Exploring Forces, p.69, 77; Physical Geography by PMF IAS, Chapter 5: Earth's Magnetic Field, p.65

2. Universal Law of Gravitation: The Pull of Mass (basic)

At its heart, the Universal Law of Gravitation tells us that gravity is not just a force that makes an apple fall to the ground; it is a fundamental property of the universe where every object with mass exerts a pull on every other object with mass. This means you, your book, the Earth, and the distant stars are all physically pulling on one another at this very moment. Because this force acts without any physical contact, we classify it as a non-contact force Science, Class VIII . NCERT (Revised ed 2025), Chapter 5: Exploring Forces, p. 72. While we usually only notice the Earth's gravity because of its massive size, the principle remains: mass creates attraction.

The most defining characteristic of gravitational force — and the one that separates it from other forces like magnetic or electrostatic forces — is that it is exclusively attractive. Unlike a magnet that can push away another magnet (repulsion) or electric charges that can repel each other, gravity never repels. It only pulls objects together Science, Class VIII . NCERT (Revised ed 2025), Chapter 5: Exploring Forces, p. 72. This is why, on an astronomical scale, gravity is the dominant force. Even though it is technically the weakest of the fundamental forces, it is additive; it keeps building up as mass increases, eventually holding entire galaxies together.

In extreme cases, the pull of mass can become so intense that it defies our standard understanding of physics. For instance, if a star is massive enough, it can reach the Chandrasekhar Limit and collapse into a singularity — a point where gravity is so strong that even light cannot escape, forming a black hole Physical Geography by PMF IAS, The Universe, The Big Bang Theory, Galaxies & Stellar Evolution, p. 7. From the simple fall of a fruit from a tree to the complex warping of spacetime, the story of gravity is essentially the story of mass reaching out to mass.

Feature	Gravitational Force	Magnetic/Electrostatic Force
Nature	Always Attractive	Attractive or Repulsive
Requirement	Mass	Charge or Magnetic Poles
Range	Infinite (Long-range)	Infinite (Long-range)

Sources: Science, Class VIII . NCERT (Revised ed 2025), Chapter 5: Exploring Forces, p.72; Physical Geography by PMF IAS, The Universe, The Big Bang Theory, Galaxies & Stellar Evolution, p.7; Themes in world history, History Class XI (NCERT 2025 ed.), Changing Cultural Traditions, p.119

3. Electric and Magnetic Forces: Charges and Poles (intermediate)

In our study of mechanics, we often focus on forces that require physical contact, like friction or tension. However, electric and magnetic forces belong to a special category called non-contact forces. These forces act through a field, meaning they can influence an object even from a distance without touching it Science, Class VIII, Exploring Forces, p.70. The fundamental 'source' of these forces is different from gravity: while gravity acts on mass, electric forces act on charges and magnetic forces act on poles.

Electric forces arise from static charges, which are categorized as 'positive' and 'negative'. A key principle here is that the interaction depends on the type of charge: unlike charges attract each other, while like charges repel each other Science, Class VIII, Exploring Forces, p.71. Similarly, magnetic forces operate between the poles of magnets. Every magnet has a North and a South pole. Just like electric charges, unlike poles attract and like poles repel Science, Class VIII, Exploring Forces, p.69. This ability to both 'push' (repel) and 'pull' (attract) is a defining feature that sets them apart from gravity.

To see how these three fundamental forces compare, look at the table below:

Feature	Gravitational Force	Electric Force	Magnetic Force
Acts on	Mass	Electric Charges (+/-)	Magnetic Poles (N/S)
Nature	Always Attractive	Attractive & Repulsive	Attractive & Repulsive
Range	Long-range (Infinite)	Long-range (Infinite)	Long-range (Infinite)

While gravity is technically the weakest of these forces, it dominates the universe on a large scale (like planets and stars) because it is always additive and attractive. In contrast, electric and magnetic forces often cancel each other out because the repulsive and attractive effects balance one another in neutral matter.

Sources: Science, Class VIII (NCERT 2025), Chapter 5: Exploring Forces, p.69, 70, 71

4. Connected Concept: Satellite Motion and Orbits (intermediate)

To understand how satellites move, we must first look at the cosmic rulebook written by Johannes Kepler. A satellite—whether it is the Moon or a man-made GPS satellite—is essentially a body in a constant state of free-fall. It moves forward with enough speed that as it falls toward Earth, the Earth's surface curves away beneath it, keeping it in a perpetual loop called an orbit. Contrary to popular belief, these orbits are not perfect circles but ellipses, with the central body (like the Sun or Earth) sitting at one of the two foci Physical Geography by PMF IAS, The Solar System, p.21.

The speed of a satellite is not constant throughout its journey. According to Kepler’s Second Law, a line connecting the satellite to the center of the planet sweeps out equal areas in equal intervals of time. This leads to a fascinating result: when a satellite is at its perigee (closest point to Earth) or a planet is at its perihelion (closest to the Sun), it moves at its maximum orbital velocity. Conversely, at the apogee (farthest point), it moves the slowest Physical Geography by PMF IAS, The Motions of The Earth and Their Effects, p.257. This variation in speed actually dictates the length of our seasons! For instance, in the Northern Hemisphere, summer is about three days longer than winter because Earth is farther from the Sun during that time, moving slower in its orbit Physical Geography by PMF IAS, The Motions of The Earth and Their Effects, p.256.

Finally, we must consider Escape Velocity. This is the minimum speed an object must reach to break free from a planet's gravitational pull entirely. If a gas molecule or a spacecraft reaches this threshold, it will not orbit; it will leave. This is why light gases like Hydrogen and Helium are scarce in our atmosphere—they easily reach escape velocity in the high-energy exosphere and leak into space Physical Geography by PMF IAS, Earths Atmosphere, p.280.

Feature	Perigee / Perihelion	Apogee / Aphelion
Distance	Closest to the central body	Farthest from the central body
Orbital Speed	Fastest	Slowest
Gravitational Pull	Strongest	Weakest

Sources: Physical Geography by PMF IAS, The Solar System, p.21; Physical Geography by PMF IAS, The Motions of The Earth and Their Effects, p.256-257; Physical Geography by PMF IAS, Earths Atmosphere, p.280

5. Connected Concept: Earth's Magnetism (intermediate)

To understand Earth's Magnetism, we must first look at the nature of forces. While gravitational force is purely attractive—acting between any two bodies with mass and pulling them together—magnetic forces are polar. They can be both attractive (unlike poles) and repulsive (like poles) Science, Class VIII NCERT (Revised ed 2025), Exploring Forces, p. 77. A magnetic field is simply the region of space where a body experiences this magnetic force Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p. 65. On a planetary scale, the Earth acts like a massive geomagnetic dipole, as if a giant bar magnet were tilted at about 11° to its rotational axis Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p. 72.

This magnetic field is not just a navigational tool; it forms the magnetosphere, a protective bubble that interacts with solar winds to shield our atmosphere Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p. 65. However, for a student of geography and physics, the most practical aspect is understanding the difference between Geographic North (the "True North" at the rotational axis) and Magnetic North (where your compass actually points). The angle between these two is called Magnetic Declination, and it varies depending on where you are on the globe Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p. 76.

Another critical concept is Magnetic Inclination, or "Dip." This is the angle the magnetic field lines make with the horizontal surface of the Earth. Imagine holding a compass needle so it can tilt up and down: at the magnetic equator, the needle stays perfectly horizontal (0° dip) because the field lines are parallel to the ground. As you move toward the magnetic poles, the needle starts to tilt until it points straight down or up (90° dip) Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p. 77.

Feature	Gravitational Force	Magnetic Force
Nature	Exclusively attractive	Attractive or Repulsive
Source	Mass	Magnetic poles/Moving charges
Range	Long-range (infinite)	Long-range (infinite)

Sources: Science, Class VIII NCERT (Revised ed 2025), Exploring Forces, p.77; Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p.65; Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p.72; Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p.76; Physical Geography by PMF IAS, Earths Magnetic Field (Geomagnetic Field), p.77

6. Comparison of Fundamental Forces: Nature, Range, and Strength (exam-level)

When we look at the universe, four fundamental forces govern every interaction, from the orbiting of planets to the bonding of atoms. In basic mechanics, we focus primarily on Gravitational, Electric, and Magnetic forces. The most striking distinction lies in their nature: while gravitational force is exclusively attractive, both electric and magnetic forces can be either attractive or repulsive. This is because gravity acts on mass, which only comes in one "flavor," whereas electric forces act on charges (positive/negative) and magnetic forces act on poles (North/South), where likes repel and opposites attract Science, Class VIII (NCERT 2025), Chapter 5, p. 72.

In terms of range, both gravitational and electromagnetic (electric/magnetic) forces are long-range forces. This means their influence theoretically extends to infinity, though their strength diminishes as the distance between objects increases. However, a fascinating paradox exists regarding their strength. Gravity is actually the weakest of the fundamental forces. Yet, it is the dominant force on an astronomical scale. Why? Because gravity is always additive; since it never repels, the gravity of every atom in a planet adds up to a massive pull. In contrast, large-scale objects are usually electrically neutral because positive and negative charges cancel each other out, limiting the reach of electric forces in the macroscopic world Science, Class VIII (NCERT 2025), Chapter 5, p. 77.

Feature	Gravitational Force	Electric / Magnetic Force
Nature	Always Attractive	Attractive or Repulsive
Range	Infinite	Infinite
Relative Strength	Very Weak	Very Strong
Acting Property	Mass	Charge / Magnetic Poles

It is also important to note that gravity is a non-contact force—it exerts its pull without physical touch Science, Class VIII (NCERT 2025), Chapter 5, p. 72. Because gravity depends on the mass of the attracting body, your weight (the measure of gravitational pull) can change if you move to a different planet, even though your mass remains constant Science, Class VIII (NCERT 2025), Chapter 5, p. 75.

Sources: Science, Class VIII (NCERT 2025), Chapter 5: Exploring Forces, p.72; Science, Class VIII (NCERT 2025), Chapter 5: Exploring Forces, p.75; Science, Class VIII (NCERT 2025), Chapter 5: Exploring Forces, p.77

7. Solving the Original PYQ (exam-level)

Now that you have mastered the fundamental nature of forces, this question brings all those building blocks together. You have learned that gravitational force is an inherent property of mass, while electric and magnetic forces arise from charges and poles. The key insight here is to look at the nature of interaction. While mass is always positive, leading to a single type of interaction, charges and magnetic poles come in pairs (positive/negative and North/South). This foundational difference dictates whether a force can only pull things together or also push them apart.

To arrive at the correct answer, (B) Gravitational force is attractive only, whereas the electric and the magnetic forces are attractive as well as repulsive, you must apply the principle of "directionality." As highlighted in Science, Class VIII. NCERT (Revised ed 2025), gravity is always an additive and attractive force regardless of the size of the objects. In contrast, electric forces repel like charges and magnetic forces repel like poles. Even though gravity is the force we feel most consistently, it is actually the weakest of the fundamental forces; it only dominates on an astronomical scale because it never "cancels out" through repulsion.

UPSC often uses common misconceptions as traps, which we see in the other options. Option (A) is a factual reversal—gravity is the weakest, not the strongest force. Options (C) and (D) attempt to confuse you regarding "range." As noted in Physical Geography by PMF IAS, both gravitational and electromagnetic forces are long-range forces that follow the inverse-square law, meaning they can be felt across vast distances. By systematically eliminating these errors regarding strength and range, you can confidently identify the unique, exclusively attractive nature of gravity.