electric field point charge

Question

Electric field at distance r from point charge Q?

RankGuru · Accepted Answer

1. **Definition**: The electric field ($E$) at a point in space is defined as the electrostatic force experienced by a unit positive test charge placed at that point.
2. **Formula from Force**: $E = F/q_{test}$.
3. **Application**: Using Coulomb's Law for a test charge $q_t$ at distance $r$ from $Q$:
   - $F = k \frac{Q q_t}{r^2}$
   - $E = \frac{k Q q_t / r^2}{q_t} = k \frac{Q}{r^2}$
4. **Conclusion**: The electric field due to a point charge follows an inverse square law, **$E = kQ/r^2$**.

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electric field point charge

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