Calculate electric current in a resistor

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SUMMARY

The discussion focuses on calculating the electric current through a 20-ohm resistor in a circuit with parallel resistors. Participants emphasize the importance of understanding series and parallel circuits, specifically the current divider rule. The current through the 20-ohm resistor is determined to be 0.18A when the total current through the parallel resistors is 0.3A. Key calculations involve finding the equivalent resistance and applying the current divider formula.

PREREQUISITES
  • Understanding of Ohm's Law
  • Knowledge of series and parallel resistor configurations
  • Familiarity with the current divider rule
  • Basic algebra for resistance calculations
NEXT STEPS
  • Study the current divider rule in detail
  • Learn how to calculate equivalent resistance in parallel circuits
  • Explore practical applications of Ohm's Law
  • Investigate the voltage divider rule for further circuit analysis
USEFUL FOR

Students studying electrical engineering, hobbyists working with circuits, and anyone needing to understand current flow in resistor networks.

nowayn
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Homework Statement


fysik_zpsf8f86f41.png

calculate the electric current in the 20 ohm resistor

The Attempt at a Solution


I have no idea where to start, but i thought maybe you should calculate the voltage first and then the voltage over the 20 ohm resistor.
 
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nowayn said:

Homework Statement


fysik_zpsf8f86f41.png

calculate the electric current in the 20 ohm resistor

The Attempt at a Solution


I have no idea where to start, but i thought maybe you should calculate the voltage first and then the voltage over the 20 ohm resistor.
You know the current through the parallel pair of resistors. How do you get from there to the current through the 20ohm resistor. You don't need voltage.
 
phinds said:
You know the current through the parallel pair of resistors.
wait so is the current there also 0,3A?
 
nowayn said:
wait so is the current there also 0,3A?
Do you understand the concepts of series elements and parallel elements? If you are not clear on that then you need to GET clear on it before trying ANY problems of this sort, else you will be perpetually confused.
 
Investigate the topic: current divider.

The current divider and the voltage divider are two concepts that you will find to be very handy to know about.
 
You don't know where to start ? Start of by calculating the parallel resistance between 20ohm and 30ohm resistor, then maybe something will click off in your mind.
 
1/20=0,05
1/30=0,0333
0,08333/0,05=0,6
resistor with 20ohms will get 60% of the current
0,3*0,6=0,18
 

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