Question

Which of the following can decrease the capacitance? Select all that apply.

(a) Increasing the plate area
(b) Increasing the distance between the plates
(c) Using a dielectric with a lower permittivity
(d) Decreasing the charge on the plates

Answer 1

Factors that can decrease capacitance include increasing the distance between plates and using a dielectric with lower permittivity. Increasing the plate area increases capacitance, and changing the charge does not directly affect it.

Step-by-step explanation:

Factors that can decrease the capacitance of a capacitor include:

• Increasing the distance between the plates: According to the formula for capacitance (C = εA/d), capacitance is inversely proportional to the distance between the plates (d). Therefore, if the distance is increased, the capacitance decreases.
• Using a dielectric with a lower permittivity: A dielectric with lower permittivity reduces the electric field strength between the capacitor plates, which results in a higher voltage for the same charge and thus a lower capacitance.

For the options provided:

• (a) Increasing the plate area would actually increase the capacitance.
• (b) Increasing the distance between the plates would decrease the capacitance.
• (c) Using a dielectric with a lower permittivity would decrease the capacitance.
• (d) Decreasing the charge on the plates does not directly decrease capacitance, as capacitance is a function of the physical properties of the capacitor.

The correct answers, those that lead to a reduction in capacitance, are (b) and (c).