Question 605: Electrostatics & Capacitance

Question

The capacitance of a capacitor with charge $q$ and a potential difference $V$ depends on

Accepted Answer

The correct answer is
Option B: the geometry of the capacitor
. Here's why:
Capacitance (denoted by *C*) is a fundamental property of a capacitor that describes its ability to store electrical energy. It's defined by the ratio of the charge stored on the capacitor (
q
) to the potential difference across its plates (
V
):
$C = \frac{q}{V}$
While the formula seems to suggest that capacitance depends on both charge and voltage, the reality is that the geometry of the capacitor determines its capacitance. Here's a breakdown:
Charge (
q
)
: The charge stored on a capacitor is directly proportional to the applied voltage. If you increase the voltage, you increase the charge stored. However, the capacitance itself remains constant for a given capacitor.
Voltage (
V
)
: Similarly, the voltage across a capacitor is directly proportional to the charge stored. Increasing the charge increases the voltage, but again, the capacitance remains unchanged.
Geometry
: The geometry of a capacitor dictates how much electric field is created between its plates for a given charge. This electric field determines the potential difference between the plates. Here are some key factors:
Area of plates (A)
: Larger plates can hold more charge for a given voltage, resulting in higher capacitance.
Distance between plates (d)
: Smaller distances between plates create a stronger electric field, which leads to higher capacitance.
Dielectric material
: The material between the plates (dielectric) affects the strength of the electric field and therefore the capacitance. A material with a higher dielectric constant increases the capacitance.
In summary, while charge and voltage are related to capacitance through the formula, they are not the determining factors. It's the capacitor's physical characteristics Ã¢ÂÂ its geometry Ã¢ÂÂ that ultimately determine its capacitance.

Answer

both $q$ and $V$

Answer

the geometry of the capacitor

Answer

$q$ only

Answer

$V$ only

Electrostatics & Capacitance

The capacitance of a capacitor with charge q and a potential difference V depends on

Choose the correct answer: