In which region magnitude of $x$ -component of electric field is maximum, if potential $(V)$ versus distance $(X)$, graph is as shown?

An electron enters between two horizontal plates separated by $2\,mm$ and having a potential difference of $1000\,V$. The force on electron is

If potential (in volts) in a region is expressed as $V (x,y,z) =6xy-y+2yz $ the electric field (in $N/C$) at point $(1, 1, 0)$ is 

If on the $x$-axis electric potential decreases uniformly from $60 \,V$ to $20 \,V$ between $x=-2 \,m$ to $x=+2 \,m$, then the magnitude of electric field at the origin

The variation of potential with distance $R$ from a fixed point is as shown below. The electric field at $R = 5\,m$ is......$volt/m$

The electric potential at a point $(x,\;y)$ in the $x - y$ plane is given by $V = - kxy$. The field intensity at a distance $r$ from the origin varies as