Solving Variable Resistance Circuit: Ohm's Law

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SUMMARY

The discussion focuses on solving a variable resistance circuit using Ohm's Law, specifically for a circuit with a total resistance of 100 ohms and a voltage drop of 12V. The key equation utilized is V=IR, where V represents voltage, I represents current, and R represents resistance. The user attempts to calculate the required resistance for two scenarios: maintaining a voltage of 12V and reducing it to 6.2V. The calculations suggest that for 12V, the current is approximately 8.5 amps, leading to a resistance of 1.41 ohms, while the resistance for 6.2V requires further clarification on the circuit configuration.

PREREQUISITES
  • Understanding of Ohm's Law (V=IR)
  • Basic knowledge of electrical circuits and components
  • Familiarity with series and parallel resistor configurations
  • Ability to perform algebraic calculations involving resistance and current
NEXT STEPS
  • Explore the concept of series and parallel resistors in circuit design
  • Learn how to calculate total resistance in complex circuits
  • Study the implications of varying voltage and resistance on current flow
  • Investigate practical applications of Ohm's Law in real-world circuits
USEFUL FOR

Students studying electrical engineering, hobbyists building circuits, and anyone looking to deepen their understanding of Ohm's Law and circuit analysis.

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Homework Statement


"A circuit has a variable resistance (total 100 ohms) across which is a voltage drop of 12 V supplied by a battery. What must be its resistance if the voltage is to be A) 12V and B) 6.2V?"

Homework Equations


V=IR


The Attempt at a Solution


We haven't learned anything besides Ohm's Law for these equations, so I tried plugging in different values to try and dial in the answers, but it didn't work. Is there something I'm missing or am I being asked to solve for two unknowns? Hints appreciated.
 
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Is that all you have? Diagram? I am assuming total resistance is 100 ohms so for 12 v you have 8.5 amps. Then for 12V, you need a resistance of 12/8.5 but I don't trust this answer. If its a serial pair of resistors where Rx and Ry are 100 ohms and you are being asked the voltage drop across Rx, i think the above is good.
 
Last edited:
drawing a blank on the diagram, literally
 

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