Which statement$(s)$ among the following are incorrect:
$(i)$ $A$ negative test charge experiences a force opposite to the direction of the field.
$(ii)$ The tangent drawn to a line of force represents the direction of electric field.
$(iii)$ The electric field lines never intersect.
$(iv)$ The electric field lines form a closed loop.

$A$ charge $q$ is placed at the centre of the open end of a cylindrical vessel. The flux of the electric field through the surface of the vessel is

Gauss's law states that

An electric dipole is placed in the north-south direction inside a sphere filled with water. Which statement is correct?

Select the correct statement$(s)$:
$(1)$ The density of electric field lines is independent of the magnitude of the electric field vector $E$ at a given point.
$(2)$ The density of electric field lines is proportional to the magnitude of the electric field vector $E$ at a given point.
$(3)$ Electric field lines do not exist in reality. They are only a graphical representation of the electric field.
$(4)$ Electric field lines exist in reality.

If the electric field is given by $\vec{E} = (5 \hat{i} + 4 \hat{j} + 9 \hat{k})$. The electric flux through a surface of area $20$ units lying in the $Y-Z$ plane will be (in units):