Advertisements
Advertisements
प्रश्न
Consider two hollow concentric spheres, S1 and S2, enclosing charges 2Q and 4Q respectively as shown in the figure. (i) Find out the ratio of the electric flux through them. (ii) How will the electric flux through the sphere S1 change if a medium of dielectric constant 'εr' is introduced in the space inside S1 in place of air ? Deduce the necessary expression
उत्तर
(i) Charge enclosed by sphere S1 = 2Q
By Gauss law, electric flux through sphere S1 is
`phi_1=(2Q)/in_0`
Charge enclosed by sphere S2 = 2Q+4Q=6Q
`:.phi_2=(6Q)/in_0`
The ratio of the electric flux is
`phi_1/phi_2=((2Q)/in_0)/((6Q)/in_0)=2/6=1/3`
(ii) For sphere S1, the electric flux is
`phi'=(2q)/in_r`
`:.(phi')/phi_1=in_0/in_r`
`=>phi'=phi_1.in_0/in_r`
∵ εr > ε0
`:.phi'
Therefore, the electric flux through the sphere S1 decreases with the introduction of the dielectric inside it.
APPEARS IN
संबंधित प्रश्न
Find out the outward flux to a point charge +q placed at the centre of a cube of side ‘a’. Why is it found to be independent of the size and shape of the surface enclosing it? Explain.
A circular ring of radius r made of a non-conducting material is placed with its axis parallel to a uniform electric field. The ring is rotated about a diameter through 180°. Does the flux of the electric field change? If yes, does it decrease or increase?
If the flux of the electric field through a closed surface is zero,
(a) the electric field must be zero everywhere on the surface
(b) the electric field may be zero everywhere on the surface
(c) the charge inside the surface must be zero
(d) the charge in the vicinity of the surface must be zero
A charge 'Q' µC is placed at the centre of a cube. The flux through one face and two opposite faces of the cube is respectively ______.
The electric flux through the surface ______.
 |
 |
 |
 |
| (i) | (ii) | (iii) | (iv) |
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 ______.
An electric charge q is placed at the center of a cube of side ℓ. The electric flux on one of its faces will be ______.
A hollow sphere of radius R has a point charge q at its centre. Electric flux emanating from the sphere is X. How will the electric flux change, if at all, when radius of the sphere is doubled?
