Question

A parallel-plate air capacitor is made by using two plates 11 cm square , spaced 3.2 mm apart. It is connected to a 12-V battery.

What is the capacitance?

Answer 1

The capacitance of a parallel-plate air capacitor with plates each 11 cm square and spaced 3.2 mm apart is approximately 3.28 pF.

Step-by-step explanation:

The question asks for the capacitance of a parallel-plate air capacitor made with two plates that are each 11 cm square and spaced 3.2 mm apart. To calculate the capacitance, we can use the formula for the capacitance of a parallel-plate capacitor, which is:

C = ε0 A / d

Where:

• ε0 is the permittivity of free space (ε0 = 8.85 x 10-12 F/m),
• A is the area of one of the plates (in meters2), and
• d is the separation between the plates (in meters).

First, we need to convert cm2 to m2 and mm to meters:

A = (11 cm x 11 cm) = (0.11 m x 0.11 m) = 0.0121 m2

d = 3.2 mm = 0.0032 m

Now, we can calculate the capacitance:

C = (8.85 x 10-12 F/m) x (0.0121 m2) / 0.0032 m

C ≈ 3.28 x 10-12 F or 3.28 pF