Current, Resistance & Potential Difference Flashcards

All 6 cards in this deck

What is the equation linking potential difference, current and resistance?

potential difference = current × resistance, or $V = IR$

What is the unit of resistance, and its symbol?

The ohm, symbol $\Omega$.

How does the current through a component change if its resistance is greater, for the same potential difference?

The current is smaller.

What are the steps to calculate the current through a component from its potential difference and resistance?
e.g. $V = 12$ V across a $4\ \Omega$ resistor

1. Write the equation: $V = IR$
2. Rearrange: $I = V/R$
3. Substitute: $I = 12/4 = 3$ A

Describe the circuit used to measure the resistance of a component.

The component in series with a cell and an ammeter, with a voltmeter connected in parallel across the component; resistance is found from $R = V/I$.

True or false? 'Voltage' is another name for potential difference.

True. Potential difference is often called voltage; both are measured in volts (V).