Advertisements
Advertisements
Question
Given the electric field in the region `vecE=2xhati`, find the net electric flux through the cube and the charge enclosed by it.

Advertisements
Solution
Since the electric field has only x component, for faces normal to x direction, the angle between E and ∆S is ±π/2. Therefore, the flux is separately zero for each face of the cube except the two shaded ones.

The magnitude of the electric field at the left face is EL = 0 (As x = 0 at the left face)
The magnitude of the electric field at the right face is ER = 2a (As x = a at the right face)
The corresponding fluxes are
`phi_L=vecE.DeltavecS=0`
`phi_R=vecE_R.DeltavecS=E_RDeltaScostheta=E_RDeltaS " "(.:theta=0^@)`
⇒ϕR= ERa2
Net flux (ϕ) through the cube = ϕL+ϕR=0+ERa2=ERa2
ϕ=2a(a)2=2a3
We can use Gauss’s law to find the total charge q inside the cube.
`phi=q/(epsilon_0)`
q=ϕε0=2a3ε0
APPEARS IN
RELATED QUESTIONS
Write S.I unit of electric flux.
Define Electric Flux.
Given a uniform electric field \[\vec{E} = 2 \times {10}^3 \ \hat{i}\] N/C, find the flux of this field through a square of side 20 cm, whose plane is parallel to the y−z plane. What would be the flux through the same square, if the plane makes an angle of 30° with the x−axis ?
Two charges of magnitudes −2Q and +Q are located at points (a, 0) and (4a, 0) respectively. What is the electric flux due to these charges through a sphere of radius ‘3a’ with its centre at the origin?
The electric field in a region is given by `vec"E"` = 5 `hatk`N/C. Calculate the electric flux Through a square of side 10.0 cm in the following cases
- The square is along the XY plane
- The square is along XZ plane
- The normal to the square makes an angle of 45° with the Z axis.
A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis. The total flux for the surface of the cylinder is given by ______.
A point charge q is placed at a distance a/2 directly above the centre of a square of side a. The electric flux through the square is ______.
In a region of space having a uniform electric field E, a hemispherical bowl of radius r is placed. The electric flux Φ through the bowl is:
The S.I. unit of electric flux is ______
