Physics 9702 · AS & A Level · Electric current

Electric current — practice question

(a)[1]

Define the term force.

(b)[1]

State the SI base units that make up force.

(c)[2]

The force $F$ between two point charges is described by $F = \dfrac{Q_1 Q_2}{4\pi r^2 \varepsilon}$. Here, $Q_1$ and $Q_2$ are the charges, $r$ is the separation between the charges, and $\varepsilon$ is a constant that depends on the medium between the charges. Use this relation to determine the base units of $\varepsilon$.

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