# How two charges of different magnitude can exert equal force [duplicate]

Though it seems to be very simple question but I want help where I am lacking.Two charges say one of 10C and other of 1C how can they exert same force.Say a charge of ten coloumb will surely attract or repel the charge of 1C with 10 times.Also keep that mass is same.

• The force is proportional to the product of the charges $\:q_{1}\cdot q_{2}\:$ and inversely proportional to the square of distance $\:r\:$ between them. Mass has nothing to do with this. Commented Apr 8, 2018 at 6:15
• mass was mentioned just to make sure that no oter forces come to play why someone mentions answer as that the heavier or lighter charge. Commented Apr 8, 2018 at 6:20

Start with charge a with charge $1\, \rm C$ and place it near charge A with charge $1\, \rm C$.
The forces on the two charges a and A have the same magnitude $F$ as required by Newton’s third law.
Remove charge a and place charge b with charge $1\, \rm C$ at exactly the same distant from charge charge A as charge a was before.
The forces on the two charges b and A have the same magnitude $F$.
The forces on the charges ab $(=2\, \rm C)$ and charge A $(=1\, \rm C)$ have the same magnitude $F+F =2F$.
Repeat the process for ten charges abcdefghij to find that the force on both charges abcdefghij $(=10\, \rm C)$ and charge A $(=1\, \rm C)$ have the same magnitude $10F$.