JEE PYQ: Current Electricity Question 8
Question 8 - 2021 (17 Mar 2021 Shift 2)
The four arms of a Wheatstone bridge have resistances as shown in the figure. A galvanometer of $15,\Omega$ resistance is connected across BD. Calculate the current through the galvanometer when a potential difference of 10 V is maintained across AC.
[Arms: AB = $100,\Omega$, BC = $10,\Omega$, AD = $60,\Omega$, DC = $5,\Omega$]
(1) $2.44,\mu\text{A}$
(2) $2.44,\text{mA}$
(3) $4.87,\text{mA}$
(4) $4.87,\mu\text{A}$
Show Answer
Answer: (3)
Solution
Using KVL: $\frac{x-10}{100} + \frac{x-y}{15} + \frac{x-0}{10} = 0$ and $\frac{y-10}{60} + \frac{y-x}{15} + \frac{y-0}{5} = 0$. Solving: $x = 0.865$, $y = 0.792$. $\Delta V = 0.073$, $R = 15,\Omega$, $i = 4.87$ mA.
BETA
