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Saturday, 31 October

JEE Main 2020 · PhysicsNumerical answerNumerical valueEasyMulti-step

JEE Main 9 January 2020, Shift 2, Physics Q23

Question 23 of 75 in this shift, Physics question 23 of 25, Section B.

In a meter bridge experiment S is a standard resistance. R is a resistance wire. It is found that balancing length is l=25l = 25 cm. If R is replaced by a wire of half length and half diameter that of R of same material, then the balancing distance l′l' (in cm) will now be ______.

The figure, in words

Meter bridge: resistance wire R in the left gap and standard resistance S in the right gap, galvanometer G with jockey, balancing length l measured from the left end, battery V connected across the bridge wire.

Official answer

40.00

NTA final key (Jan 2020).

Chapter
Current Electricity
Topic
Wheatstone Bridge
Idea tested
Meter Bridge Principles

Same idea in other shifts

Asked 7× in all
  1. 1 Feb 2024, Shift 2 · Q50In a metre-bridge when a resistance in the left gap is 2 Ω2\,\Omega and unknown resistance in the right gap, the balance length is found to…MediumSingle correct
  2. 31 Jan 2024, Shift 2 · Q49The resistance per centimeter of a meter bridge wire is rr, with X ΩX\ \Omega resistance in left gap. Balancing length from left end is at…MediumSingle correct
  3. 26 Jul 2022, Shift 1 · Q56Resistances are connected in a meter bridge circuit as shown in the figure. The balancing length l1l_1 is 40 cm. Now an unknown resistance…MediumNumerical valueHas a figure
  4. 27 Jul 2022, Shift 1 · Q51In a meter bridge experiment, for measuring unknown resistance 'S', the null point is obtained at a distance 30 cm from the left side as…EasyNumerical valueHas a figure
  5. 27 Jul 2022, Shift 2 · Q52In the given figure of meter bridge experiment, the balancing length AC corresponding to null deflection of the galvanometer is 40 cm. The…MediumNumerical valueHas a figure
  6. 18 Mar 2021, Shift 2 · Q26Consider a 72 cm long wire AB as shown in the figure. The galvanometer jockey is placed at P on AB at a distance xx cm from A. The…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.