Ohm’s law: series and parallel circuits

Theory

Ohm’s law: $V=RI$. In series the current is the same and the voltages add: $R_{eq}=R_1+R_2+R_3$. In parallel the voltage is the same and the currents add: $\frac{1}{R_{eq}}=\sum \frac{1}{R_i}$. Power: $P=VI=I^{2}R=V^2/R$.

What to observe

• In series, the largest resistor glows the most ($P=I^{2}R$).
• In parallel, the smallest resistor glows the most ($P=V^2/R$).

Try this

• Open the switch and watch the current stop.
• Switch to the mixed connection.

Also available in: Lei de Ohm: circuitos em série e em paralelo (Português) · Ley de Ohm: circuitos en serie y en paralelo (Español)