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
Advertisements
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.
"The outward electric flux due to charge +Q is independent of the shape and size of the surface which encloses is." Give two reasons to justify this statement.
Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface of the box is 8.0 × 103 N m2/C.
- What is the net charge inside the box?
- If the net outward flux through the surface of the box were zero, could you conclude that there were no charges inside the box? Why or Why not?
Two charges of magnitudes +4Q and − Q are located at points (a, 0) and (− 3a, 0) respectively. What is the electric flux due to these charges through a sphere of radius ‘2a’ with its centre at the origin?
Following Figure (a) shows an imaginary cube of edge L/2. A uniformly charged rod of length (L) moves towards the left at a small but constant speed `nu.` At t = 0, the left end just touches the centre of the face of the cube opposite it. Which of the graphs shown in the figure (b) represents the flux of the electric field through the cube as the rod goes through it?
The electric flux through a closed Gaussian surface depends upon ______.
The total flux through the faces of the cube with side of length a if a charge q is placed at corner A of the cube is ______.
Total electric flux coming out of a unit positive charge kept in air is ______.
The electric field intensity due to an infinite cylinder of radius R and having charge q per unit length at a distance rir r(r > R) from its axis is ______.
An electric field is given by `(6 hat i + 5 hat j + 3 hat k)` N/C. The electric flux through a surface area `30 hat i` m2 lying in YZ-plane (in SI unit) is ______.
