Physics · Electrostatics

The electric field intensity (E) due to an infinite sheet of charge is given by the formula E = σ / (2ε₀), where σ is the surface charge density and ε₀ is the permittivity of free space. When the surface charge density increases by 25%, the new charge density becomes 1.25σ. Substituting this into the formula, we find that the new electric field intensity becomes E' = 1.25σ / (2ε₀) = 1.25E, indicating that the electric field intensity increases by 25% as well. Therefore, Option A is correct. The other options incorrectly suggest other changes, but they do not reflect the direct proportionality between electric field intensity and surface charge density.

This option is correct because the electric field intensity is directly proportional to the surface charge density. Therefore, a 25% increase in surface charge density results in a 25% increase in electric field intensity.

This option is incorrect. The electric field intensity only increases in direct proportion to the change in surface charge density, which in this case is 25%, not 50%.

This option is incorrect. An increase in surface charge density will not result in a decrease in electric field intensity.

This option is incorrect. The electric field intensity changes with the surface charge density; thus, if the surface charge density increases, the electric field cannot remain constant.