Fundamental Forces �In Nature

There are four fundamental forces, in nature.

• Strong nuclear
• Electromagnetic
• Weak nuclear
• Gravitational

​

Strong nuclear forces

• They hold the nucleons inside the nucleus
• They are strongest forces among all the forces
• They are short range forces
• They are always attractive forces
• They are spin dependent
• They are charge independent
• They are non central forces

Electromagnetic forces

• They cause electric and magnetic effects
• They can attractive or repulsive
• Like charges repel each other
• Opposite charges attract each other
• Weaker than the strong nuclear force
• They act over a much larger distances than the strong nuclear forces

They are the forces between charged particles

They are responsible for atomic and molecular structures

​

​

Electromagnetic forces

Weak nuclear forces

• Responsible for nuclear decay
• Weak nuclear forces between two elementary particles
• They are very short distance range
• electrons and neutrino interact with each other through Weak nuclear forces

Weak nuclear forces

Gravitational forces

• Weakest among all the fundamental forces,
• They act over very large distances
• Always attractive
• Act between any two pieces of matter in the universe
• They are the cause for motion of planets around the sun , tides in the sea etc
• Very important in explaining the structure of the universe

Remember…

• The weak nuclear force is NOT the weakest of the fundamental forces.
• GRAVITY is the weakest force, but most important in understanding how objects in the universe interact.

Relative Strengths

F_g : F_w : F_e : F_s = 1 : 10²⁵ : 10³⁶ : 10³⁸

Q1. Which is the strongest force in nature?

(a) Weak nuclear force

(b) Strong nuclear force

(c) Gravitational force

(d) Electromagnetic force

Q2. Which is the weakest force in nature?

(a) Weak nuclear force

(b) Strong nuclear force

(c) Gravitational force

(d) Electromagnetic force