Current Flashcards

All 6 cards in this deck

What is electric current?

The rate of flow of charge.

What is the current in a metal a flow of?

Electrons (free electrons moving through the metal).

How must an ammeter be connected to measure the current in a component, and what unit does it read?

In series with the component; it reads current in amps (A).

What is the equation linking charge, current and time, with units?

charge (C) = current (A) $\times$ time (s), $Q = I \times t$.

What are the steps to find the charge that flows when the current is given in mA and the time in minutes?

e.g. 500 mA for 2 minutes

1. Convert mA to A (divide by 1000): $500\,\mathrm{mA} = 0.5\,\mathrm{A}$
2. Convert minutes to seconds ($\times 60$): $2\,\mathrm{min} = 120\,\mathrm{s}$
3. $Q = I \times t = 0.5 \times 120 = 60\,\mathrm{C}$

True or false? Conventional current is drawn as flowing from the negative terminal to the positive terminal of a cell.

False. Conventional current goes from positive to negative; the electrons flow the opposite way.