Question

Two large metal plates of area 1.2 m^2 face each other, 6.5 cm apart, with equal charge magnitudes but opposite signs. The field magnitude E between them (neglect fringing) is 68 N/C. Find |q|.

Answer 1

Q= 722.5 *10⁻¹² C

Step-by-step explanation:

Conceptual analysis

For a parallel plate capacitor, we can use the following formula :

E= (Q) /(ϵ₀*A) Formula (1)

Where:

E: electric field between the plates ( N/C)

Q: Charge of the plates (C)

ϵo : vacuum permittivity ( C²/ N.m²)

A : area oh the plates (m²)

Known data

A = 1.2 m²

E= 68 N/C

ϵo= 8.8542*10⁻¹² ( C²/ N.m²)

Problem development

We apply the formula (1) :

`68= (Q)/((8.8542*10^(-12) )(1.2))`

Q= (68) (8.8542*10⁻¹²)(1.2)

Q= 722.5 *10⁻¹² C