Question

Define the term electric flux. Write its SI unit. [Foreign 2017]

Answer 1

Answer:

Explanation:

The no. of electric field lines passing perpendicular to a plane surface known as Electric flux.

Denoted by-Φ

Φ= E.A

E= F/Q.A

SI unit is Nm²/c

Answer 2

Solution :

$\underline{\boxed{\bf{\red{Electric}\:\purple{Flux}\:\green{:}}}}$

▪ Electric flux through a plane surface area S held in a uniform electric field $\bf{\vec{E}}$ is

$\underline{\boxed{\bf{\pink{\phi_E=\vec{E}\:{\tiny\bullet}\:\vec{S}=ES\cos\theta}}}}$

where $\theta$ is the angle which the normal to the outward drawn normal to surface area S makes with the field $\bf{\vec{E}}$.

▶ According to Gauss's theorem, the total electric flux through a closed surface $\bf{\vec{S}}$ enclosing charge q is

$\displaystyle\underline{\boxed{\bf{\orange{\phi_E=\int{\vec{E}\:{\tiny\bullet}\:\vec{dS}=\dfrac{\phi_E}{\epsilon_o}}}}}}$

In other words, Electric flux is defined as numbers of field lines associated with specific surface area.

SI unit of (Φ) = $\bf{\gray{Nm^2C^{-1}}}$

Additional information :-

▪ Flux density is defined as

______________________________

| Flux density = Total flux / Area |