Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Atoms and Nuclei question

2024 · 30 Jan · Shift 1 · Q61
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Physics
  4. /Atoms and Nuclei
  5. /2024 · 30 Jan · Shift 1 · Q61

Atoms and Nuclei question

2024 · 30 Jan · Shift 1 · Q61

JEE MainPhysicsAtoms and NucleiMCQ+4 / −1
The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the 5th excited state of a hydrogen atom is :
  1. A
    4
  2. B
    1
  3. C
    12\frac{1}{2}21​
  4. D
    14\frac{1}{4}41​
View written solutionFree

Correct answer: C

  1. Identify the state

The 5th excited state means: n=6n = 6n=6 because ground state is n=1n=1n=1, first excited is n=2n=2n=2, etc.

  1. Use Bohr model energy relations for hydrogen atom

For an electron in a hydrogen atom:

  • Total energy: E=K+UE = K + UE=K+U
  • Potential energy: U=−2KU = -2KU=−2K
  • Hence, E=K+U=K−2K=−KE = K + U = K - 2K = -KE=K+U=K−2K=−K

So the magnitude of potential energy is: ∣U∣=2K|U| = 2K∣U∣=2K

Therefore, K∣U∣=K2K=12\frac{K}{|U|} = \frac{K}{2K} = \frac{1}{2}∣U∣K​=2KK​=21​

  1. Required ratio

The question asks for the ratio of the magnitude of kinetic energy to the potential energy. Interpreting this as: magnitude of kinetic energymagnitude of potential energy=K∣U∣=12\frac{\text{magnitude of kinetic energy}}{\text{magnitude of potential energy}} = \frac{K}{|U|} = \frac{1}{2}magnitude of potential energymagnitude of kinetic energy​=∣U∣K​=21​

This ratio is independent of nnn, so even for the 5th excited state, it remains the same.

  1. Check options
  • A: 444 ❌
  • B: 111 ❌
  • C: 12\frac{1}{2}21​ ✅
  • D: 14\frac{1}{4}41​ ❌

Therefore, the correct answer is: 12\boxed{\frac{1}{2}}21​​

PreviousNext

More from Atoms and Nuclei

  • A electron of hydrogen atom on an excited state is having energy En​=−0.85 eV. The maximum number of allowed transitions to lower energy level is ​.2024 · Numerical
  • An electron revolving in nth  Bohr orbit has magnetic moment μn​. If μn​∝nx, the value of x is2024 · MCQ
  • In a nuclear fission reaction of an isotope of mass M, three similar daughter nuclei of same mass are formed. The speed of a daughter nuclei in terms of mass defect ΔM will be :2024 · MCQ
  • If the wavelength of the first member of Lyman series of hydrogen is λ. The wavelength of the second member will be2024 · MCQ
  • The mass defect in a particular reaction is 0.4 g. The amount of energy liberated is n×107 kWh, where n=​. (speed of light =3×108 m/s)2024 · Numerical
  • The mass number of nucleus having radius equal to half of the radius of nucleus with mass number 192 is :2024 · MCQ
  • A nucleus has mass number A1​ and volume V1​. Another nucleus has mass number A2​ and Volume V2​. If relation between mass number is A2​=4A1​, then V1​V2​​=​.2024 · Numerical
  • The mass of proton, neutron and helium nucleus are respectively 1.0073 u,1.0087 u and 4.0015 u. The binding energy of helium nucleus is :2023 · MCQ