1. Tardigrade
  2. Question
  3. Physics
  4. In the circuit shown, a four-wire potentiometer is made of a 400 cm long wire, which extends between A and B. The resistance per unit length of the potentiometer wire is r = 0.01 Ω/cm. If an ideal voltmeter is connected as shown with jockey J at 50 cm from end A, the expected reading of the voltmeter will be :

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. In the circuit shown, a four-wire potentiometer is made of a $400\, cm$ long wire, which extends between $A$ and $B$. The resistance per unit length of the potentiometer wire is $r = 0.01 $ $\Omega/cm$. If an ideal voltmeter is connected as shown with jockey $J$ at $50\, cm$ from end $A$, the expected reading of the voltmeter will be :Physics Question Image

JEE MainJEE Main 2019Current Electricity

Solution:

Resistance of wire $AB = 400 \times 0.01 = 4 \Omega$
$ i = \frac{3}{6} = 0.5 A$
Now voltmeter reading = $i$ (Resistance of 50 cm length)
$ = (0.5 A) (0.01 \times 50) = 0.25$ volt

Solution Image