Series Circuit

In a series circuit:

• The current is the same through every component: $I_1 = I_2 = I_3$
• The total potential difference is shared: $V_{\text{total}} = V_1 + V_2 + V_3$
• The total resistance is the sum: $R_{\text{total}} = R_1 + R_2 + R_3$

If one component breaks, the whole circuit stops working because there is only one path for the current.

Christmas tree lights used to be wired in series. If one bulb failed, all went out.