Q21.A particle of mass 200 MeV c−2 collides with a hydrogen atom at rest. Soon after the collision, the particle comes to rest, and the atom recoils and goes to its first excited state. The initial kinetic energy of the particle (in eV ) is N4 . The value of N is: (Given the mass of the hydrogen atom to be 1 GeV c−2 )......... → + 2ˆj + m . Then the magnitude of torque about the point N acts at a point (4ˆi + 3ˆj −ˆk)
What This Question Tests
This multi-concept question combines inelastic collision principles with energy conservation, including the internal energy change of a hydrogen atom going to an excited state. It requires careful handling of units.
Concepts Tested
Formulas Used
m₁v₁ = m₂v₂
KE_initial = KE_final + ΔE
E_n = -13.6/n² eV
📚 NCERT Sections This Tests
12.5 — A Hydrogen Atom Initially In The Ground Level Absorbs A Photon,
Physics Class 12 · Chapter 12
12.5 A hydrogen atom initially in the ground level absorbs a photon, which excites it to the n = 4 level. Determine the wavelength and frequency of photon.
12.4 — The Ground State Energy Of Hydrogen Atom Is –13.6 Ev. What Are The
Physics Class 12 · Chapter 12
12.4 The ground state energy of hydrogen atom is –13.6 eV. What are the kinetic and potential energies of the electron in this state?
13.5 — The Q Value Of A Nuclear Reaction A + B ® C + D Is Defined By
Physics Class 12 · Chapter 13
13.5 The Q value of a nuclear reaction A + b ® C + d is defined by Q = [ mA + mb – mC – md]c2 where the masses refer to the respective nuclei. Determine from the given data the Q-value of the following reactions and state whether the reactions are exothermic or endothermic. (i) 11 H+13 H →12 H+12 H (ii) 126 C+126 C →1020 Ne+ 24 He Atomic masses are given to be m ( 12 H ) = 2.014102 u m ( 13 H) = 3.016049 u m ( 126 C ) = 12.000000 u m ( 1020 Ne ) = 19.992439 u
📋 Question Details
- Chapter
- Centre of Mass & Collisions
- Topic
- Inelastic collision and energy conservation
- Year
- 2020
- Shift
- 05 Sep Shift 1
- Q Number
- Q21
- Type
- Numerical
- NCERT Ref
- Class 11 Physics Ch 7: System of Particles and Rotational Motion; Class 12 Physics Ch 12: Atoms
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