Which of the following is a non-contact force?

Question

Which of the following is a non-contact force?

1. A. Magnetic force (Correct answer)
2. B. Frictional force
3. C. Impact force
4. D. None of these

Correct Answer

Option A — Magnetic force

Detailed Solution & Explanation

The correct answer is Magnetic force.

Key Points

• Magnetic force is a non-contact force — a magnet can attract or repel magnetic materials (or another magnet) without physically touching them, acting across the space of its magnetic field.
• Other examples of non-contact forces are gravitational force and electrostatic force.
• In contrast, frictional force and impact force are contact forces, because they act only when two objects are in direct physical contact (friction acts between surfaces sliding over each other, and impact force acts during a collision).
• Since the question asks for a force that acts without contact, the answer is Magnetic force, option (A).

Additional Information

• Non-contact (field) forces act across a distance: gravitational, magnetic and electrostatic.
• Contact forces require touching: friction, tension, normal reaction, air resistance and applied muscular force.
• Field forces are described by an inverse-square law in both the gravitational and electrostatic cases, which is why their formulas look so similar.