- #31
AdityaDev
- 527
- 33
That is what we want. Now the potential difference across the resistors will be different.Faris Shajahan said:
Measuring resistance using potentiometer
- Thread starter AdityaDev
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The discussion revolves around measuring resistance using a potentiometer and the confusion surrounding current and voltage relationships in different resistor setups. Participants debate why the balancing length changes when different resistances are used, with some asserting that the current remains the same while others argue it varies due to internal resistance. The concept of terminal voltage versus electromotive force (emf) is highlighted, emphasizing that the potentiometer measures terminal voltage, which differs based on resistance. A suggestion is made to include a rheostat in the circuit to maintain constant current for accurate measurements. Ultimately, the conversation underscores the complexity of understanding these electrical principles in practical applications.
- #32
andrevdh
- 2,126
- 116
Usually this experiment is done with the resistors connected in series to the cell, in which case the
current will be the same through both resistors.
For this particular setup I can only reduce it to two unknowns, the resistance X, and the internal resistance of the cell.
current will be the same through both resistors.
For this particular setup I can only reduce it to two unknowns, the resistance X, and the internal resistance of the cell.
- #33
Faris Shajahan
- 29
- 4
AdityaDev said:
Yes, it will be different but still it would be impossible for us to calculate the value of ##X## as we don't have the value of ##r## given in the question.
Instead if they say there is a rheostat in series with ε in order to maintain constant current in both the cases, then we can calculate ##X## as
##X=R\frac{l_2}{l_1}##
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