In a potentiometer experiment, a cell in the secondary circuit gives null point at 2.5 m when the length of the potentiometer wire is 10 m. If the length of the potentiometer wire is increased by 1 m without changing the cell in the primary circuit, then the position of the null point will be

Question

In a potentiometer experiment, a cell in the secondary circuit gives null point at 2.5 m when the length of the potentiometer wire is 10 m. If the length of the potentiometer wire is increased by 1 m without changing the cell in the primary circuit, then the position of the null point will be, 3.5 m, 3 m, 2.75 m, 2 m

MARKS App · Accepted Answer

The resistance of a potentiometer wire is given as, R = ρ × l A R ' = 2 .5 ρ A × 10 Potential V ' = I × R ' , = I ⁡ 2.5 ρ A ⁡ × 10 Now, again the length of potentiometer wire is increased by 1 m , then the resistance of null position wire. R ' ' = ρ × l 11 × A V " = IR " and, V ' = V " I × 2 .5 ρ A × 10 = I × ρ × l 11 × A 2 .5 × 11 10 = l = 2.75 m

Search any question & find its solution

Looking for more such questions to practice?