JEE PYQ: Current Electricity Question 32
Question 32 - 2020 (08 Jan 2020 Shift 1)
Four resistances of $15,\Omega$, $12,\Omega$, $4,\Omega$ and $10,\Omega$ respectively in cyclic order to form Wheatstone’s network. The resistance that is to be connected in parallel with the resistance of $10,\Omega$ to balance the network is ____ $\Omega$.
Show Answer
Answer: 10
Solution
For balance: $\frac{P}{Q} = \frac{S}{R}$, i.e., $\frac{15}{12} = \frac{S}{4}$, $S = 5$. $R’$ in parallel with $10,\Omega$ gives $5,\Omega$: $\frac{10R’}{10+R’} = 5$. $10R’ = 50 + 5R’$. $R’ = 10,\Omega$.
BETA
