JEE Main 2020 · PhysicsNumerical answerNumerical valueMediumMulti-step

JEE Main 8 January 2020, Shift 2, Physics Q24

Question 24 of 75 in this shift, Physics question 24 of 25, Section B.

The series combination of two batteries, both of the same emf

10\ \mathrm{V}

, but different internal resistance of

20\ \Omega

and

5\ \Omega

, is connected to the parallel combination of two resistors

30\ \Omega

and

R\ \Omega

. The voltage difference across the battery of internal resistance

20\ \Omega

is zero, the value of R (in

\Omega

) is __________.

Official answer

30.00

NTA final key (Jan 2020).

Chapter: Current Electricity
Topic: Kirchhoff's Laws
Idea tested: Series Combination of Cells

Same idea in other shifts

Asked 4× in all

3 Apr 2025, Shift 2 · Q48Two cells of emfs 1 V and 2 V and internal resistances $2\ \Omega$ and $1\ \Omega$ , respectively, are connected in series with an external…MediumNumerical value
25 Jun 2022, Shift 2 · Q39Two cells of same emf but different internal resistances $r_1$ and $r_2$ are connected in series with a resistance $R$ . The value of…MediumSingle correct
27 Aug 2021, Shift 1 · Q12Five identical cells each of internal resistance 1 $\Omega$ and emf 5 V are connected in series and in parallel with an external…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.