Explain the advantages of connecting lamps in parallel in a lighting circuit

4.3.2 Series and Parallel Circuits

What is a Parallel Circuit?

In a parallel circuit, each component (like a lamp) is connected across the same two points, so every lamp gets the full supply voltage. Think of it as a group of roads branching from a main highway – each road starts and ends at the same two points, so traffic (current) can flow independently on each road. 🚗💡

Key Formulae

Ohm’s law: \$V = IR\$

Total resistance in parallel: \$\displaystyle \frac{1}{R{\text{total}}} = \frac{1}{R1} + \frac{1}{R_2} + \dots\$

Current through one lamp: \$I{\text{lamp}} = \frac{V{\text{supply}}}{R_{\text{lamp}}}\$

Series vs. Parallel – Quick Comparison

Why Connect Lamps in Parallel? 🔌💡

• Consistent Brightness: Every lamp receives the full supply voltage, so they all shine at the same brightness.
• Independent Operation: If one lamp burns out, the others keep lighting up – no total blackout.
• Easy Replacement: Swap out a single lamp without affecting the rest of the circuit.
• Safety: Lower risk of overloading a single path; current splits across multiple paths.

Real‑World Analogy 🌆

Picture a city street with streetlights. In a parallel layout, each streetlight is wired directly to the power source. If one light fails, the others stay lit, keeping the street safe. In a series layout, all lights would be on a single line; if one fails, the whole line goes dark – not ideal for safety or convenience. 🚦