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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceOtherMediumConceptual

JEE Main 4 August 2021, Shift 2, Physics Q2

Question 2 of 90 in this shift, Physics question 2 of 30, Section A.

For an electron orbiting around the nucleus in a hydrogen like atom with atomic number Z; T, U and E denote the kinetic, potential and total energy respectively of the electron. Which of the following statements are valid in this context ? (A) T, U is same for all orbits (B) T + U is same for all orbits (C) 2T + U is same for all orbits (D) E + U is same for all orbits (E) E + T is same for all orbits Choose the most appropriate answer from the options given below :
  1. (1)(B) only
  2. (2)(C) only
  3. (3)(A) and (D) only
  4. (4)(C) and (E) onlyOfficial answer

Official answer

Option 4

NTA final key.

Chapter
Atoms
Topic
Bohr's Atomic Model
Idea tested
Energy Ratios in Bohr Orbits

Same idea in other shifts

Asked 5× in all
  1. 5 Apr 2024, Shift 1 · Q48An electron rotates in a circle around a nucleus having positive charge Ze. Correct relation between total energy (E) of electron to its…EasySingle correct
  2. 30 Jan 2024, Shift 1 · Q47The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the 5th5^{\mathrm{th}} excited state of a…EasySingle correct
  3. 24 Jun 2022, Shift 2 · Q50In Bohr’s atomic model of hydrogen, let K, P and E are the kinetic energy, potential energy and total energy of the electron respectively.…EasySingle correct
  4. 4 Aug 2021, Shift 2 · Q30In the Bohr’s atomic model, second energy state potential energy of hydrogen is (–E). the kinetic energy of electron in the first energy…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.