Question
A potentiometer circuit is set up as shown. The potential gradient across the potentiometer wire is k volt /cm and the ammeter, present in the circuit, reads 1.0 A when the two-way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1 and 3, is plugged in, are found to be at lengths l1 and l2 cm respectively. The magnitudes, of the resistor R and X, in ohm, are then, equal respectively, to
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k (l2 -l1) and kl2
-
kl1 and k (l2-l1)
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k (l2 - l1) and kl1
-
kl1 and kl2
Solution
B.
kl1 and k (l2-l1)
The balancing length for R (When 1, 2 are connected) be is l1 and balancing length for R + x (when 1, 3 is connected is l2)
