Question

Consider the following forces-(a) Force of friction, (b) Collision forces, (c) Normal reaction generated by the surface and (d) Tension in strings.
Which of these are electromagnetic forces?

• A. Only (a), (c) and (d)
• B. Only (b)
• C. All (a), (b), (c) and (d)
• D. Only (c) and (d)

Hint:

Contact forces arise from electric interactions between atoms and molecules of the bodies in contact.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Friction, collision forces, normal reaction and tension are all contact forces.

Step 2: Their origin
When surfaces or neighbouring atoms in a string come very close, the charges in their atoms attract or repel each other.

Step 3: Conclusion
At the microscopic level, every one of these forces is electromagnetic. Gravity and nuclear forces play no role here.

Final Answer:
All four forces (a), (b), (c) and (d) are electromagnetic. \[ \boxed{\text{(C) }\text{All (a), (b), (c) and (d)}} \]