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Saturday, 31 October

JEE Main 2022 · PhysicsNumerical answerNumerical valueMediumMulti-step

JEE Main 28 June 2022, Shift 2, Physics Q55

Question 55 of 90 in this shift, Physics question 25 of 30, Section B.

All resistances in figure are 1 Ω each. The value of current ‘I’ is a5\frac{a}{5} A. The value of a is __________.

The figure, in words

A 3 V battery (+ terminal at top) with current I marked upward, in series with one resistor; the circuit then branches as a tree: 1 resistor splits into 2 branches each with a resistor, each of those splits into 2 (4 resistors), each of those splits into 2 (8 resistors); all 8 end branches join at one common node on the right, which is connected by a wire back to the battery.

Official answer

8

NTA final key.

Chapter
Current Electricity
Topic
Kirchhoff's Laws
Idea tested
Circuit Symmetry Analysis

Same idea in other shifts

Asked 8× in all
  1. 9 Apr 2024, Shift 2 · Q43The effective resistance between AA and BB, if resistance of each resistor is RR, will be :MediumSingle correctHas a figure
  2. 10 Apr 2023, Shift 1 · Q50The equivalent resistance of the circuit shown below between points aa and bb is :MediumDiagram basedHas a figure
  3. 25 Jun 2022, Shift 1 · Q58The total current supplied to the circuit as shown in figure by the 5 V battery is __________ A.MediumNumerical valueHas a figure
  4. 26 Jun 2022, Shift 2 · Q41The equivalent resistance between points A and B in the given network is :MediumDiagram basedHas a figure
  5. 26 Aug 2021, Shift 1 · Q12In the given figure, the emf of the cell is 2.2 V and if internal resistance is 0.6 Ω\Omega. Calculate the power dissipated in the whole…MediumDiagram basedHas a figure
  6. 27 Aug 2021, Shift 2 · Q21The ratio of the equivalent resistance of the network (shown in figure) between the points a and b when switch is open and switch is…MediumNumerical valueHas a figure
  7. 26 Feb 2021, Shift 1 · Q15Five equal resistances are connected in a network as shown in figure. The net resistance between the points A and B is :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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.