How Do You Calculate Current and Power in Parallel Resistors?

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SUMMARY

The discussion focuses on calculating current and power in a parallel resistor circuit involving two resistors of 42 ohms and 64 ohms. Given that the current through the 64-ohm resistor is 3A, the total resistance can be calculated using the formula 1/(R.total) = 1/(R.1) + 1/(R.2). The voltage across both resistors remains constant, allowing the use of Ohm's Law (V = IR) to find the current through the 42-ohm resistor and the total power supplied by the circuit.

PREREQUISITES
  • Understanding of Ohm's Law (V = IR)
  • Knowledge of parallel resistor calculations
  • Familiarity with power calculations (P = IV)
  • Basic algebra skills for manipulating equations
NEXT STEPS
  • Learn how to calculate total resistance in circuits with more than two resistors in parallel
  • Study power calculations in electrical circuits, specifically using P = IV
  • Explore the implications of voltage drop across parallel resistors
  • Investigate the effects of varying resistor values on current distribution in parallel circuits
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Electrical engineering students, hobbyists working on circuit design, and anyone seeking to understand the principles of current and power in parallel resistor configurations.

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Homework Statement



2) 2 resistors, 42 and 64 ohms, are connected in parallel. The current through the 64 resistor is 3A. Determine the current in the other esistor and what is the total power supplied by the two resistors?

Homework Equations





The Attempt at a Solution




2) How could i possibly have enough info to do this one?
 
Last edited:
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1, Whats the overall resistance of 2 resistors in parallel (extend this to 3 resistors)?
 
The resistance is not the same if the pieces are connected in parallel.

Resistors connected in parallel follow the law

1/(R.total)=1/(R.1)+1/(R.2)+1/(R.3)...

Where R.total is the total resistanse and R.1 is the resistanse of the first resistor, R.2 is the resistanse of the second resistor etc. etc.
 
thanks figured that one out, can you help me with the second one?
 
Assume the same voltage across both resistors.
Then V=IR for the known and I =V/R for the unknown.
(it should also be obvious how to skip a step)
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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