31. You are putting up your Christmas tree and decide to begin untangling the lights sc wrap them around your tree. Once you untangle them, you plug them in to make st working. Unfortunately,none of the lights seem to light up! You look carefully at th lights and realize that one light bulb seems to be loose. You screw the light bulb ba suddenly the whole strand lights up. How are your Christmas lights connected? Bri why they were not lit up when the bulb was loose. (/2T) __

The Christmas lights are connected in a **series circuit**.<br /><br />When the bulb was loose, it created a break in the circuit. In a series circuit, the electric current flows through each light bulb in a single continuous pathway. If any part of that pathway is broken (like with the loose bulb), the current cannot flow through *any* of the bulbs, and therefore none of them will light up. Tightening the loose bulb closed the break in the circuit, allowing the current to flow through all the bulbs and light them up.<br />