JEE Main 2022 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 27 July 2022, Shift 1, Physics Q41

Question 41 of 90 in this shift, Physics question 11 of 30, Section A.

Two sources of equal emfs are connected in series. This combination is connected to an external resistance R. The internal resistances of the two sources are

r_1

and

r_2

(

r_1 > r_2

). If the potential difference across the source of internal resistance

r_1

is zero, then the value of R will be :

(1) $r_1 - r_2$ Official answer
(2) $\frac{r_1r_2}{r_1+r_2}$
(3) $\frac{r_1+r_2}{2}$
(4) $r_2 - r_1$

Official answer

Option 1

NTA final key.

Chapter: Current Electricity
Topic: Kirchhoff's Laws
Idea tested: Cell EMF and Internal Resistance

Same idea in other shifts

Asked 10× in all

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11 Apr 2023, Shift 2 · Q59Two identical cells each of emf $1.5\ \mathrm{V}$ are connected in series across a $10\ \Omega$ resistance. An ideal voltmeter connected…MediumNumerical value
30 Jul 2022, Shift 2 · Q24A cell sends a current through a resistance 4 Ω for time t and sends current through another resistance 16 Ω for the same time t.If the…MediumNumerical value
27 Aug 2021, Shift 1 · Q26First, a set of n equal resistors of 10 $\Omega$ each are connected in series to a battery of emf 20 V and internal resistance 10…MediumNumerical value
22 Jul 2021, Shift 2 · Q27In an electric circuit, a cell of certain emf provides a potential difference of 1.25 V across a load resistance of 5 $\Omega$ . However,…EasyNumerical value
17 Mar 2021, Shift 2 · Q2Two cells of emf 2E and E with internal resistance $\mathrm{r_1}$ and $\mathrm{r_2}$ respectively are connected in series to an external…MediumDiagram basedHas a figure

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.