JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 18 March 2021, Shift 2, Physics Q5

Question 5 of 90 in this shift, Physics question 5 of 30, Section A.

If the angular velocity of earth’s spin is increased such that the bodies at the equator start floating, the duration of the day would be approximately : [Take g

=10

^{-2}

, the radius of earth, R

=6400\times10^3

m, Take

\pi=3.14

]

(1)does not change
(2)1200 minutes
(3)60 minutes
(4)84 minutesOfficial answer

Official answer

Option 4

NTA final key.

Chapter: Gravitation
Topic: Orbital Mechanics
Idea tested: Orbital Time Period

Same idea in other shifts

Asked 10× in all

2 Apr 2026, Shift 1 · Q30A planet ( $P_1$ ) is moving around the star of mass $2M$ in the orbit of radius $R$ . Another planet ( $P_2$ ) is moving around another star…EasySingle correct
4 Apr 2024, Shift 2 · Q37Correct formula for height of a satellite from earths surface is:MediumSingle correct
10 Apr 2023, Shift 2 · Q37The time period of a satellite, revolving above earth's surface at a height equal to R will be (Given $g = \pi^2$ m/s $^2$ , R = radius of…MediumSingle correct
29 Jun 2022, Shift 2 · Q40The time period of a satellite revolving around earth in a given orbit is 7 hours. If the radius of orbit is increased to three times its…EasySingle correct
3 Aug 2021, Shift 1 · Q28The time period of a satellite of earth is 10 hours. If the separation between the earth and the satellite is increased to 16 times the…EasyNumerical value
24 Feb 2021, Shift 1 · Q5Consider two satellites $S_1$ and $S_2$ with periods of revolution 1 hr. and 8 hr. respectively revolving around a planet in circular…EasySingle correct
25 Feb 2021, Shift 1 · Q6Two satellites A and B of masses 200 kg and 400 kg are revolving round the earth at height of 600 km and 1600 km respectively. If $T_A$ …MediumSingle correctHas a figure
17 Mar 2021, Shift 2 · Q4A geostationary satellite is orbiting around an arbitary planet 'P' at a height of 11R above the surface of 'P', R being the radius of…EasySingle correct

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.