Electrical power of a lightbulb

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SUMMARY

The discussion focuses on calculating the electrical power of two identical light bulbs connected in series versus parallel. When connected in series, the total resistance is 2R, while in parallel, the equivalent resistance is R/2. The power ratio between the two configurations is established as 1:4, confirming that the bulbs in parallel consume four times the power of those in series. The relevant formulas used include P=I²R and P=V²/R.

PREREQUISITES
  • Understanding of electrical resistance and Ohm's Law
  • Familiarity with series and parallel circuit configurations
  • Knowledge of power calculations in electrical circuits
  • Basic algebra for manipulating equations
NEXT STEPS
  • Study the concept of equivalent resistance in parallel circuits
  • Learn about power distribution in series vs. parallel circuits
  • Explore practical applications of series and parallel circuits in electronics
  • Investigate the impact of different resistor values on circuit performance
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Students studying electrical engineering, educators teaching circuit theory, and hobbyists interested in electronics and circuit design.

Firye Stanly
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Homework Statement


Two identical light bulbs are connected to the ends of the battery. In the first case they are connected in series and in the second they are connected in parallel mode. What is the ratio of the electrical power of light bulbs connected as mentioned?

Homework Equations


##P=I^2R##
##P=\frac{V^2}{R}##

The Attempt at a Solution


Since the voltage is the same and i take a light bulb to be a resistor shouldn't it just be ##R_1/R_2##? It somehow should be 1/4 but i don't get how. Total resistance in the first case is ##2R## and in the second is ##2/R## right?
 
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In the second case, total resistance is not 2/R. What is the formula for equivalent resistance of two parallel resistors?
 
cnh1995 said:
In the second case, total resistance is not 2/R. What is the formula for equivalent resistance of two parallel resistors?
Parallel resistors ##1/R_t = 1/R+1/R## so its ##R/2## so its ##1/4## oh thanks!
 

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