Ahmed wants to shift the balance point of a potentiometre from the fourth wire to the fifth wire to measure the resistance of a cell.Which of the following options is CORRECT with respect to the electric current and the type of cell from which the current has been drawn?
Correct answer: A. The current is flowing from a standard cell with lower internal resistance compared to the cell under test.
- A. The current is flowing from a standard cell with lower internal resistance compared to the cell under test.
- B. The current is flowing from a standard cell with higher internal resistance compared to the cell under test.
- C. The cell from which the current is drawn has no impact on the balance point of a potentiometer.
- D. The current is drawn equally from both a standard cell and the cell under test.
Explanation
The correct answer is Option A. In a potentiometer setup, the balance point is determined by the reference voltage from a standard cell and the voltage across the cell under test. A standard cell with lower internal resistance provides a stable reference voltage, allowing for precise measurement of the cell's resistance by shifting the balance point effectively. Option B is incorrect because a higher internal resistance in the standard cell would result in an unstable reference voltage, making it difficult to accurately shift the balance point. Option C is incorrect because the cell characteristics do impact the potentiometer's balance point. Option D is incorrect because the balance point is determined by a singular reference voltage, not by drawing current equally from both cells.
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