JEE PYQ: Current Electricity Question 44
Question 44 - 2019 (09 Apr 2019 Shift 2)
A metal wire of resistance $3,\Omega$ is elongated to make a uniform wire of double its previous length. This new wire is now bent and the ends joined to make a circle. If two points on the circle make an angle $60°$ at the centre, the equivalent resistance between these two points will be:
(1) $\frac{12}{5},\Omega$
(2) $\frac{5}{2},\Omega$
(3) $\frac{5}{3},\Omega$
(4) $\frac{7}{2},\Omega$
Show Answer
Answer: (3)
Solution
When length doubles, resistance becomes $4 \times 3 = 12,\Omega$. $R_{\text{eq}} = \frac{2 \times 10}{12} = \frac{5}{3},\Omega$ (resistances of $\frac{60}{360} \times 12 = 2,\Omega$ and $10,\Omega$ in parallel).
BETA
