The diagram shows the equipotential lines for two equal and opposite charges. Draw the electric field lines for these two charges.

The two long plates are separated by a distance of $15.0 \mathrm{cm}$. The bottom plate is kept at a potential of $-250 \mathrm{V}$ and the top at $+250 \mathrm{V}$. A charge $-2.00 \mathrm{\mu C}$ is placed at a point  $3.00 \mathrm{cm}$ from the bottom plate.

Find the electric potential energy of the charge.

The two long plates are separated by a distance of $15.0 \mathrm{cm}$. The bottom plate is kept at a potential of $-250 \mathrm{V}$ and the top at $+250 \mathrm{V}$. A charge $-2.00 \mathrm{\mu C}$ is placed at a point  $3.00 \mathrm{cm}$ from the bottom plate.

The charge is then moved vertically up to a point $3.00 \mathrm{cm}$ from the top plate.

What is the electric potential energy of the charge now $?$

The two long plates are separated by a distance of $15.0 \mathrm{cm}$. The bottom plate is kept at a potential of $-250 \mathrm{V}$ and the top at $+250 \mathrm{V}$. A charge $-2.00 \mathrm{\mu C}$ is placed at a point  $3.00 \mathrm{cm}$ from the bottom plate.

The charge is then moved vertically up to a point $3.00 \mathrm{cm}$ from the top plate.

How much work was done on the charge $?$

An electron is shot with a speed equal to $1.59\times {10}^6 \mathrm{m} {\mathrm{s}}^{-1}$ from a point where the electric potential is zero towards an immovable negative charge $q$ (see the diagram).

Determine the potential at $P$ so that the electron stops momentarily at $P$ and turns back. (Use $m_e=9.1\times {10}^{-31} \mathrm{kg}$

An electron is shot with a speed equal to $1.59\times {10}^6 \mathrm{m} {\mathrm{s}}^{-1}$ from a point where the electric potential is zero towards an immovable negative charge $q$ (see the diagram).

Calculate the magnitude of $q$. (use $m_e=9.1\times {10}^{-31} \mathrm{kg}$, $K=9\times {10}^9 \mathrm{N} {\mathrm{m}}^2 {\mathrm{c}}^{-2}$)

Two equal and opposite charges are placed at points with coordinates $x=0$, $y=a$ and $x=0$, $y=-a$ as shown in the diagram.

Find the electric field at the point with coordinates $x=d, y=0$.

Two equal and opposite charges are placed at points with coordinates $x=0$, $y=a$ and $x=0$, $y=-a$ as shown in the diagram.

Find the electric field at the point with coordinates $x=d, y=0$. for two equal negative charges $-q$ on the $y-$axis.

Two equal and opposite charges are placed at points with coordinates $x=0$, $y=a$ and $x=0$, $y=-a$ as shown in the diagram.

Sketch the graph to show the variation of these fields with the distance $d$.