NDA 2 2024 GAT, question 63

Topic: Physics

Q63

Two resistances of $5.0\ Ω$ and $7.0\ Ω$ are connected in series and the combination is connected in parallel with a resistance of $36.0\ Ω$ . The equivalent resistance of the combination of three resistors is

(a) $24.0\ Ω$
(b) $12.0\ Ω$
(c) $9.0\ Ω$ Correct answer
(d) $6.0\ Ω$

Solution.

Answer: (c) $9.0\ Ω$

The series pair is 5+7=12 Ω.
In parallel with 36 Ω, the equivalent is (12×36)/(12+36)=432/48=9 Ω.
It is smaller than either parallel branch, as expected.