Question 316: Electrostats & Capacitance

Question

A parallel plate capacitor is made of two circular plates separated by a distance $$5$$ $$mm$$ and with a dielectric of dielectric constant $$2.2$$ between them. When the electric field in the dielectric is $$3 	imes {10^4}\,V/m$$ the charge density of the positive plate will be close to:

Accepted Answer

Electric field in presence of dielectric between the two plates of a parallel plate capacitor is given by,
$$E = {\sigma  \over {K{\varepsilon _0}}}$$
Then, charge density
$$\sigma  = K{\varepsilon _0}E$$
$$ = 2.2 	imes 8.85 	imes {10^{ - 12}} 	imes 3 	imes {10^4} \approx 6 	imes {10^{ - 7}}\,\,C/{m^2}$$

Answer

$$6 	imes {10^{ - 7}}\,\,C/{m^2}$$

Answer

$$3 	imes {10^{ - 7}}\,\,C/{m^2}$$

Answer

$$3 	imes {10^4}\,\,C/{m^2}$$

Answer

$$6 	imes {10^4}\,\,C/{m^2}$$

Electrostats & Capacitance

A parallel plate capacitor is made of two circular plates separated by a distance $5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 3 \times {10^4}\,V/m$ the charge density of the positive plate will be close to:

Choose the correct answer: