How Do Voltage and Current Behave in Series and Parallel Light Bulb Circuits?

  • Thread starter Thread starter Fire Slayer
  • Start date Start date
  • Tags Tags
    Light
AI Thread Summary
In a parallel circuit with two light bulbs rated at 30W and 40W, each bulb experiences the same voltage of 120V, resulting in different currents based on their power ratings. The resistance for each bulb can be calculated using the formula R = V^2 / P, yielding specific values for both bulbs. In contrast, when connected in series, the total voltage of 120V is divided between the bulbs, leading to a shared current throughout the circuit. The voltage drop across each bulb in series is proportional to its resistance, affecting the overall brightness. Understanding these behaviors is crucial for analyzing circuit performance in different configurations.
Fire Slayer
Messages
7
Reaction score
0

Homework Statement


Two Light bulbs, one rated 30W at 120V and another rated 40W at 120V are arranged in two different circuits.
a) they bulbs are connected in parallel to a 120V source

determine the resistance and current in both bulbs.

b) determine the resistance and current if they are connected in series


Homework Equations


P=IV

V=IR


The Attempt at a Solution



I took the power over the voltage to find the current and then plugged that into V=IR, but how does the voltage and current differ when it splits, or when it is in series?
 
Physics news on Phys.org
The load voltages for a parallel configuration is the same across each load. Each light in the parallel configuration has the same voltage.

For a series configuration the load voltages add to equal the source voltage.
 
Thread 'Help with Time-Independent Perturbation Theory "Good" States Proof'

Thread 'Help with Time-Independent Perturbation Theory "Good" States Proof'

(Disclaimer: this is not a HW question. I am self-studying, and this felt like the type of question I've seen in this forum. If there is somewhere better for me to share this doubt, please let me know and I'll transfer it right away.) I am currently reviewing Chapter 7 of Introduction to QM by Griffiths. I have been stuck for an hour or so trying to understand the last paragraph of this proof (pls check the attached file). It claims that we can express Ψ_{γ}(0) as a linear combination of...
View full post »

Similar threads

Why do the headlights on the car become dim when the car is starting?
Replies
4
Views
2K
B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?
Replies
12
Views
2K
Determining the Change in Bulb Brightness by Changing Circuit
Replies
6
Views
1K
Engineering Combination circuit with Series & Parallel light bulbs
Replies
4
Views
2K
I Does Ohm's Law work for Light Bulbs?
2
Replies
57
Views
12K
Current flowing in an open circuit
Replies
9
Views
1K
Current, voltage : brightness of bulb in parallel or series
Replies
2
Views
4K
Which bulb will glow brighter in a series and parallel circuit?
Replies
5
Views
2K
How to find the power consumed by the light bulb
Replies
19
Views
3K
I Energy Flow From Battery to the Light Bulb
Replies
16
Views
5K

Hot Threads

Recent Insights

Back
Top