for a gaussin surface through which the net flux is zero the following 4 statements could be true which of the statements must be true a)tere are no charges inside the surface b)the net charge inside the surface is 0 c)the electric field is 0 everywhere on the surface d)the number of electric field lines entering the surface eguals the nuber leaving the surface
what is the forces between two smalls spheres having charges of 2 × 10 -7 C and 3 × 10- 7 c placed 30cm apart in air ?
To determine which of the statements must be true for a Gaussian surface through which the net flux is zero, let's understand the concept of Gauss's law and the implications of zero net flux.
Gauss's law states that the net electric flux through a closed surface is directly proportional to the total electric charge enclosed by that surface. Mathematically, it is given by:
Φ = ε0 * Qenc,
where Φ is the net electric flux, ε0 is the permittivity of free space, and Qenc is the total charge enclosed.
Now, if the net flux through a Gaussian surface is zero, it means that the enclosed charge is also zero (Qenc = 0). This fact leads us to conclude the following:
a) Statement a) "There are no charges inside the surface" must be true. If there were charges inside the surface, the flux would not be zero.
b) Statement b) "The net charge inside the surface is 0" must be true. Since the enclosed charge is zero for zero net flux, there cannot be any net charge inside the surface.
c) Statement c) "The electric field is 0 everywhere on the surface" does not necessarily have to be true for a Gaussian surface with zero net flux. The electric field can be zero or non-zero on the surface, as long as the total charge enclosed is zero.
d) Statement d) "The number of electric field lines entering the surface equals the number leaving the surface" must be true. If the net flux through the surface is zero, it implies that the number of electric field lines entering the surface is equal to the number leaving the surface. This is a consequence of the conservation of electric flux.
To summarize, statements a), b), and d) must be true for a Gaussian surface with zero net flux. Statement c) does not necessarily have to be true.