Tutorial 1

ELEC2300

Some Formula Maybe not on the Formula Sheet

$${\vec{E}}_{dipole}=-\frac{2kqd}{x^2}$$

2.2 - Parallel Plate Capacitor

Note

Uniform field if not close to ‘ends’ of the capacitor. Generally ignore the fringing (the magnetic fields from the side of the capcitor).

$$\nabla V_{ba}=V_b-V_a=-{\int }_A^B\vec{E}\cdot dl$$

If we move one of the parallel plate further and further away, the electric field strength will be the same.

$$C=\frac{Q}{\Delta V}$$ $$\Delta V=\frac{Qd}{At}$$

Adding these together gives

$$C=\frac{At}{d}$$

2.4 Dielectrics and Electric Susceptibility

${\vec{E}}_{total}={\vec{E}}_{induced}+{\vec{E}}_0$ $E_0$ is the initial field (external field).

$$K=\frac{E_0}{}$$ $$\Delta V=\frac{\Delta V_0}{K}$$