JEE Main202228 Jun 2022Morning ShiftPhysicsCurrent ElectricityActual
A meter bridge setup is shown in the figure. It is used to determine an unknown resistance R using a given resistor of 15   Ω . The galvanometer G shows null defection when tapping key is at 43   cm mark from end A . If the end correction for end A is 2   cm , then the determined value of R will be Ω .
Correct answer
19
Step-by-step solution
Using the conditions of a balanced wheatstone bridge and adding the end correction. 15 R = l + e L + e - l + e ⇒ 15 43 + 2 = R 102 - 45 ⇒ R = 57 45 × 15 ⇒ R = 19   Ω