The electric potential $(V)$ as a function of distance $(x)$ [in meters] is given by $V = (5x^2 + 10 x -9)\, Volt$. The value of electric field at $x = 1\, m$ would be......$Volt/m$

A parallel plate capacitor is charged to a potential difference of $100\ V$ and disconnected from the source of emf. A slab of dielectric is then inserted between the plates. Which of the following three quantities change?

$(i)$ The potential difference
$(ii)$ The capacitance
$(iii)$ The charge on the plates

Two identical charged spherical drops each of capacitance $C$ merge to form a single drop. The resultant capacitance

A point charge $q$ is placed at a distance $\frac{a}{2}$ directly above the centre of a  square of side $a$ . The electric flux through the square is

Two point charges $+q$ and $-q$ are held fixed at $(-d, 0)$ and $(+d, 0)$ respectively of a $(x, y)$ coordinate system. Then

A parallel plate condenser with plate area $A$ and separation $d$ is filled with two dielectric materials as shown in the figure. The dielectric constants are $K_1$ and $K_2$ respectively. The capacitance will be