AP EAMCET · PHYSICS · Current Electricity
The null point of a potentiometer with a cell of emf \(\varepsilon\) is obtained at a distance \(l\) on the wire, then
- A \(\varepsilon \propto l\)
- B \(\varepsilon \propto l^2\)
- C \(\varepsilon \propto \frac{1}{l}\)
- D \(\varepsilon \propto \frac{1}{l^2}\)
Answer & Solution
Correct Answer
(A) \(\varepsilon \propto l\)
Step-by-step Solution
Detailed explanation
As we know, electric field, \(E=-\frac{d V}{d r}\) Hence, emf \(\varepsilon\) is also directly proportional to \(l\) i.e., \(\varepsilon \propto l\).
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