State what electric field strength means.
In a vacuum, two point charges A and B are separated by $15\text{ cm}$, as shown in Fig. 5.1. Point P is on the line joining the charges and is at a distance $x$ from charge A. Fig. 5.2 shows how the electric field strength $E$ at point P varies with distance $x$.
Using the direction of the electric field, state and explain whether charges A and B have the same signs or opposite signs.
State why the electric field strength between $x = 3\text{ cm}$ and $x = 7\text{ cm}$ does not obey an inverse-square law, even though charge A is a point charge.
Use Fig. 5.2 to find the ratio $\dfrac{\text{magnitude of charge A}}{\text{magnitude of charge B}}$.
Using the direction of the electric field, state and explain whether charges A and B have the same signs or opposite signs.
State why the electric field strength between $x = 3\,\text{cm}$ and $x = 7\,\text{cm}$ does not obey an inverse-square law, even though charge A is a point charge.
Use Fig. 5.2 to find the ratio $\dfrac{\text{magnitude of charge A}}{\text{magnitude of charge B}}$.