The current has only one loop to flow through, like a string of Christmas lights, is called a

• A. Parallel Circuit
• B. Series Circuit
• C. Mixed Circuit
• D. Circular Circuit

Answer: (B)

When there’s only one path for the current to take, all the components are in a single loop. This arrangement is called a series circuit: the same current flows through every part, and the total resistance is the sum of the individual resistances. A string of Christmas lights illustrates this, since the current must pass through each bulb in sequence. If one bulb breaks the path, the circuit opens and the whole string goes dark. In contrast, a parallel circuit provides multiple paths for current, so the current can split between branches; a mixed circuit has both kinds of paths, and a “circular circuit” isn’t a standard term.