$(a)$ An electrostatic field line is a continuous curve. That is, a field line cannot have sudden breaks. Why not?
$(b)$ Explain why two field lines never cross each other at any point?
$(a)$ An electrostatic field line is a continuous curve because a charge experiences a continuous force when traced in an electrostatic field. The field line cannot have sudden breaks because the charge moves continuously and does not jump from one point to the other.
$(b)$ If two field lines cross each other at a point, then electric field intensity will show two directions at that point. This is not possible. Hence, two field lines never cross each other.
Given below are two statements:
Statement $I :$ An electric dipole is placed at the centre of a hollow sphere. The flux of electric field through the sphere is zero but the electric field is not zero anywhere in the sphere.
Statement $II :$ If $R$ is the radius of a solid metallic sphere and $Q$ be the total charge on it. The electric field at any point on the spherical surface of radius $r ( < R )$ is zero but the electric flux passing through this closed spherical surface of radius $r$ is not zero.
In the light of the above statements, choose the correct answer from the options given below:
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
If $\oint_s \vec{E} \cdot \overrightarrow{d S}=0$ over a surface, then:
Three charges $q_1 = 1\,\mu c, q_2 = 2\,\mu c$ and $q_3 = -3\,\mu c$ and four surfaces $S_1, S_2 ,S_3$ and $S_4$ are shown in figure. The flux emerging through surface $S_2$ in $N-m^2/C$ is
Electric field in a region is uniform and is given by $\vec{E}=a \hat{i}+b \hat{j}+c \hat{k}$. Electric flux associated with a surface of area $\vec{A}=\pi R^2 \hat{i}$ is