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Saturday, 31 October

JEE Main 2020 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 9 January 2020, Shift 1, Physics Q20

Question 20 of 75 in this shift, Physics question 20 of 25, Section A.

In the given circuit diagram, a wire is joining points B and D. The current in this wire is :

The figure, in words

Circuit diagram: a rectangle-like loop with corner/junction points A (left), B (top middle), C (right) and D (bottom middle). Between A and B on the top branch is a resistor labelled 1 Ω; between B and C on the top branch a resistor labelled 2 Ω; between A and D on the lower branch a resistor labelled 4 Ω; between D and C on the lower branch a resistor labelled 3 Ω. A plain wire (vertical line) joins B and D. A battery labelled 20 V is connected in the outer wire running from A down and across the bottom to C.
  1. (1)zero
  2. (2)22AOfficial answer
  3. (3)44A
  4. (4)0.40.4A

Official answer

Option 2

NTA final key (Jan 2020).

Chapter
Current Electricity
Topic
Wheatstone Bridge
Idea tested
Unbalanced Bridge Analysis

Same idea in other shifts

Asked 4× in all
  1. 15 Apr 2023, Shift 1 · Q60A network of four resistances is connected to 9 V battery, as shown in figure. The magnitude of voltage difference between the points A…MediumNumerical valueHas a figure
  2. 17 Mar 2021, Shift 2 · Q16The four arms of a Wheatstone bridge have resistances as shown in the figure. A galvanometer of 15 Ω\Omega resistance is connected across…HardDiagram basedHas a figure
  3. 4 Sep 2020, Shift 2 · Q23Four resistances 40 Ω\Omega, 60 Ω\Omega, 90 Ω\Omega and 110 Ω\Omega make the arms of a quadrilateral ABCD. Across AC is a battery of…EasyNumerical valueHas 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.