State the precautions which must be taken in using a potentiometer.

1.	State the precautions which must be taken in using a potentiometer.
Answer» Precautions to be taken in using a potentiometer: 1. The potential difference across the potentiometer wire must be greater than the emf or potential difference to be balanced. Hence, in comparing emfs, the driver emf E > E₁ , E₂ (direct method) or E > E₁ + E₂ (combination method). 2. The positive terminal of the cell with emf E₁ and that with emf E₂ , or their combination, must be connected to the higher potential terminal of the potentiometer. 3. The potentiometer wire must be of uniform cross section and homogeneous. 4. The potentiometer wire should be long and have a high resistivity and low temperature coefficient of resistance.

Answer»

Precautions to be taken in using a potentiometer:

1. The potential difference across the potentiometer wire must be greater than the emf or potential difference to be balanced. Hence, in comparing emfs, the driver emf E > E₁ , E₂ (direct method) or E > E₁ + E₂ (combination method).

2. The positive terminal of the cell with emf E₁ and that with emf E₂ , or their combination, must be connected to the higher potential terminal of the potentiometer.

3. The potentiometer wire must be of uniform cross section and homogeneous.

4. The potentiometer wire should be long and have a high resistivity and low temperature coefficient of resistance.

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