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A potentiometer is an accurate and versa...

A potentiometer is an accurate and versatile device to make electrical measurements of `E.M.F.` because the method involves
(a) cells
(b) potential gradients
(c) a condition of no current flow through the galvanometer
(d) a combination of cells, galvanometer and resistance

A

cells

B

potential gradients

C

a condition of no current flow through the galvanometer

D

a combination of cells, galvanometer and resistance

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding why a potentiometer is an accurate and versatile device for measuring EMF, we can analyze the options provided and determine the most appropriate answer. ### Step-by-Step Solution: 1. **Understanding the Potentiometer**: A potentiometer is a device used to measure the electromotive force (EMF) of a cell or the potential difference between two points in an electric circuit without drawing any current from the circuit. **Hint**: Remember that a potentiometer is used for measuring potential differences and EMF. 2. **Analyzing the Options**: - **(a) Cells**: While cells are part of the setup, they do not explain why the potentiometer is accurate. - **(b) Potential Gradients**: This refers to the change in potential over a distance but does not directly address the accuracy of EMF measurement. - **(c) A condition of no current flow through the galvanometer**: This is a key feature of the potentiometer. It ensures that the measurement does not affect the circuit, leading to accurate readings. - **(d) A combination of cells, galvanometer, and resistance**: This describes the components of a potentiometer but does not explain why it is accurate. 3. **Identifying the Correct Answer**: The most significant reason for the potentiometer's accuracy in measuring EMF is that it operates under the condition of no current flow through the galvanometer. This condition allows for precise measurements without affecting the circuit. Therefore, the correct answer is **(c) a condition of no current flow through the galvanometer**. ### Final Answer: The correct answer is **(c) a condition of no current flow through the galvanometer**.
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