JEE Main 2021 · PhysicsNumerical answerNumerical valueEasyCalculation

JEE Main 17 March 2021, Shift 1, Physics Q26

Question 26 of 90 in this shift, Physics question 26 of 30, Section B.

The radius in kilometer to which the present radius of earth (R = 6400 km) to be compressed so that the escape velocity is increased 10 times is __________ .

Official answer

NTA final key.

Chapter: Gravitation
Topic: Gravitational Potential
Idea tested: Escape Velocity and Potential Relation

Same idea in other shifts

Asked 8× in all

2 Apr 2026, Shift 2 · Q31If a body of mass 1 kg falls on the earth from infinity, it attains velocity (v) and kinetic energy (k) on reaching the surface of earth.…MediumSingle correct
4 Apr 2025, Shift 2 · Q29An object is kept at rest at a distance of 3R above the earth's surface where R is earth's radius. The minimum speed with which it must be…MediumSingle correct
6 Apr 2024, Shift 1 · Q33To project a body of mass m from earth's surface to infinity, the required kinetic energy is (assume, the radius of earth is $R_E$ , g =…EasySingle correct
13 Apr 2023, Shift 1 · Q36A planet having mass 9 Me and radius $4R_e$ , where Me and Re are mass and radius of earth respectively, has escape velocity in km/s given…EasySingle correct
31 Aug 2021, Shift 1 · Q17The masses and radii of the earth and moon are ( $M_1$ , $R_1$ ) and ( $M_2$ , $R_2$ ) respectively. Their centres are at a distance 'r' apart.…MediumSingle correct
25 Feb 2021, Shift 1 · Q1Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : The escape velocities…EasyAssertion–reason
8 Jan 2020, Shift 2 · Q22An asteroid is moving directly towards the centre of the earth. When at a distance of 10 R (R is the radius of the earth) from the earths…MediumNumerical value

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.