On charging a soap bubble its size:

CONCEPT:

• Electric charge: It is an intrinsic property of the elementary particles of matter which gives rise to electric force between various objects.
• It is a scalar quantity.
• SI unit of electric charge is coulomb (C).
• The total charge on the conductor is given by q = It, when current flows through the conductor for some time.

Where I = current and t = time

EXPLANATION:

• When a soap bubble is charged, then the charged particle will uniformly be distributed over the surface of the soap bubble.
• Hence the radius of the soap bubble will increase because the charged particles are uniformly distributed on the soap bubble and this will cause them to repel each other due to the electrostatic force. Therefore option 2 is correct.