A charge Q is to be divided on two objects. What should be the values of the charges on the objects so that the force between the objects is maximum?

CONCEPT:

• Coulomb law: If two stationary and point charges Q₁ and Q₂ are kept at a distance r, then it is found that force of attraction or repulsion between them is mathematical, Force between point charges:

Where, F = force between them, k = proportionality constant = 9 × 10⁹ Nm²/C², r = distance between charges.

• Opposite charges attract each other
• Same charges repel each other
• When charges are brought in contact, they share charges in an equal ratio.

EXPLANATION:

Let one object receive q and another object receive (Q – q) of charge.

The force between the objects is

Where r is the distance between the charges,

Now for F to be maximum

This means

Thus for maximum force charge must be divided equally onto two objects.

So option 1 is correct.