Question

A spherical rubber balloon carries a charge, uniformly distributed over the surface. As the balloon is blown up and increases in size, the total electric flux coming out of the surface ______.

Options

• increases

• remains unchanged

• becomes zero

• decreases

Answer 1

A spherical rubber balloon carries a charge, uniformly distributed over the surface. As the balloon is blown up and increases in size, the total electric flux coming out of the surface remains unchanged.

Explanation:

The electric field intensity due to point charge q placed at the centre of a sphere of radius r,

E = `1/(4piε_0) "q"/"r"^2`

As balloon is blown up, charge enclosed by the Gaussian surface remains same. So, electric field intensity remains the same. The electric flux is given by

Φ = E · dS

⇒ Φ ∝ E

As, E remains same, the flux remains unchanged.