Unexpected change in potential difference across a parallel circuit

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SUMMARY

The discussion centers on an unexpected drop in potential difference across a parallel circuit during a physics lab experiment. The battery used was rated at 6V, but the measured potential differences were 5.6V with one resistor, 4.7V with two, 4.5V with three, and 3.9V with four resistors connected. This phenomenon contradicts the principle that potential difference remains constant in parallel circuits. The likely explanation involves the internal resistance of the battery and the increased current draw as more resistors are added.

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  • Understanding of Ohm's Law
  • Knowledge of parallel circuit configurations
  • Familiarity with internal resistance concepts
  • Basic principles of electrical current and voltage
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  • Research the effects of internal resistance in batteries
  • Study the behavior of current in parallel circuits
  • Explore methods to measure potential difference accurately
  • Learn about circuit analysis techniques using Kirchhoff's laws
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Hello, I have just completed a physics lab in which I was trying to prove that the potential difference across a parallel circuit remains constant regardless of how many resistors are connected in the circuit. The potential difference of the battery is 6V. As I connected the resistors, starting with one and increasing to four, the potential difference dropped. With one resistor is was about 5.6 V, with two it was about 4.7 V, with three it was about 4.5 V, and with four it was about 3.9 V. I know this is not supposed to happen. I made sure that I connected everything correctly and I did.

Can anyone help me understand why this happened?
Thank you
 
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Consider the internal resistance of the battery and the increased current drawn as you add resistors.
 

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