JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 27 August 2021, Shift 1, Physics Q12

Question 12 of 90 in this shift, Physics question 12 of 30, Section A.

Five identical cells each of internal resistance 1

\Omega

and emf 5 V are connected in series and in parallel with an external resistance ‘R’. For what value of ‘R’, current in series and parallel combination will remain the same ?

(1)1 $\Omega$ Official answer
(2)5 $\Omega$
(3)10 $\Omega$
(4)25 $\Omega$

Official answer

Option 1

NTA final key.

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
8 Jan 2020, Shift 2 · Q24The series combination of two batteries, both of the same emf $10\ \mathrm{V}$ , but different internal resistance of $20\ \Omega$ and…MediumNumerical value

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.