Chapter 35, Problem 29A

Will the current in a lightbulb connected to a 220-V source be greater or less than that in the same bulb when it is connected to a 110-V source?

To determine

Whether the current in a light bulb greater or less for $220\text{V}$ than $110\text{V}$ for the same bulb.

Explanation of Solution

Introduction:

The current in a circuit is directly proportional to the voltage across the circuit for the same resistance. If the voltage increases or decreases, then the current also increases or decreases in the circuit.

The bulb is the same for both voltage ratings. So, the resistance remains constant for both the voltage ratings.

The current through the circuit is the flow of electrons across the circuit. The flow of electrons varies with the potential difference across the circuit. If the potential difference across the circuit increases or decreases, then the flow of electrons also increases or decreases.

The voltage rating of $220\text{V}$ is greater than the voltage rating of $110\text{V}$ across the bulb. So, the greater current will pass through the bulb for voltage rating of $220\text{V}$ due to the fast flow of electrons.

Conclusion:

The greater current in a light bulb for voltage rating of $220\text{V}$ than voltage rating of $110\text{V}$ .