JEE Main 2024 · PhysicsMultiple choiceSingle correctMediumConceptual

JEE Main 31 January 2024, Shift 2, Physics Q49

Question 49 of 90 in this shift, Physics question 19 of 30, Section A.

The resistance per centimeter of a meter bridge wire is

r

, with

X\ \Omega

resistance in left gap. Balancing length from left end is at 40 cm with

25\ \Omega

resistance in right gap. Now the wire is replaced by another wire of

2r

resistance per centimeter. The new balancing length for same settings will be at

(1)80 cm
(2)20 cm
(3)10 cm
(4)40 cmOfficial answer

Official answer

Option 4

NTA final key.

Chapter: Current Electricity
Topic: Wheatstone Bridge
Idea tested: Meter Bridge Principles

Same idea in other shifts

Asked 7× in all

1 Feb 2024, Shift 2 · Q50In a metre-bridge when a resistance in the left gap is $2\,\Omega$ and unknown resistance in the right gap, the balance length is found to…MediumSingle correct
26 Jul 2022, Shift 1 · Q56Resistances are connected in a meter bridge circuit as shown in the figure. The balancing length $l_1$ is 40 cm. Now an unknown resistance…MediumNumerical valueHas a figure
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
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
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 $x$ cm from A. The…EasyNumerical valueHas a figure
9 Jan 2020, Shift 2 · Q23In a meter bridge experiment S is a standard resistance. R is a resistance wire. It is found that balancing length is $l = 25$ cm. If R is…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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.