Question

Which of the following extent agencies can exert forces on a body even from a distance?
1. Stream
2. Wind
3. Hands
4. Magnetic forces

Answer 1

Correct Answer - Option 4 : Magnetic forces

Concept:

Force: Force is an external effect in the form of a push or pulls that:

1. Produces or tries to produce motion in a body at rest.
2. Stops or tries to stop a moving body.
3. Changes or tries to change the direction of motion of the body.

There are two types of forces based on their applications:

Contact forces are those types of forces that result when the two interacting objects are in contact with each other physically. 

• Example: Friction force, tension force, Normal force, etc.

Non-Contact Force - It is a force that acts on an object without coming physically in contact with it.

• eg: Gravitational Force, Electrostatic force, Magnetic force

Explanation

• The magnetic force is the force exerted by the charged body when it moves in a magnetic field. It is called non-contact force because it attracts the objects which do not require that objects in physical contact with each other. 
• All other forces i.e. wind, streams and hand, requires contact.