Question

For a ‘n’ particle system how many pairs of particles are required to calculate the total potential energy of system of n particle ?

Answer 1

nC2

Explanation:

• For a ‘n’ particle system nC2 pairs of particles are required to calculate the total potential energy of system of n particle.
• For any number of particles, the number of ways in which we can choose any 2 particles at a given time without considering the order is nC2.

Example:

If we consider n is 4, then the number of pairs of particles for energy will be:

q1q2, q1q3, q1q4 , q2q3, q2q4, and q3q4

nC2 = 4C2 = 6