Download App

12. atoms — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics12. atoms1 Mark
MCQ
The wavelength of radiation emitted is $\lambda_0$ when an electron jumps from third to second orbit of hydrogen atom. For the electron to jump from the fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be
  • A
    $\frac{16}{25} \lambda_0$
  • ✓
    $\frac{20}{27} \lambda_0$
  • C
    $\frac{27}{20} \lambda_0$
  • D
    $\frac{25}{16} \lambda_0$
✓

Answer

Correct option: B.
$\frac{20}{27} \lambda_0$
b
(b)

$\frac{1}{\lambda_0}=R\left(\frac{1}{2^2}-\frac{1}{3^2}\right)$

$\frac{1}{\lambda_0}=R \frac{5}{36}$

$\frac{1}{\lambda_1}=R\left(\frac{1}{2^2}-\frac{1}{4^2}\right)$

$\frac{1}{\lambda_1}=R\left(\frac{1}{4}-\frac{1}{16}\right)$

$\frac{1}{\lambda_1}=R \frac{3}{16}$

$\frac{\lambda_1}{\lambda_0}=\frac{5}{36} \times \frac{16}{3}$

$\lambda_1=\frac{20}{27} \lambda_0$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 12. atoms→12. atoms — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

Which of the following is vector quantity
→
A mark at the bottom of a liquid appears to rise by 0.1 m. The depth of the liquid is 1 m. The refractive index of the liquid is
→
In the given figure each plate of capacitance C has partial value of charge
→
The earth’s magnetic field at a given point is $0.5 \times {10^{ - 5}}\,Wb{\rm{ - }}{m^{ - 2}}$. This field is to be annulled by magnetic induction at the center of a circular conducting loop of radius $5.0\,cm$. The current required to be flown in the loop is nearly......$A$
→
A hole is :
→
A rod of length 20 cm is rotating with angular speed of 100 rps in a magnetic field of strength 0.5 T about it’s one end. What is the potential difference between two ends of the rod
→
Assertion : Mass of moving photon varies inversely as the wavelength.
Reason : Energy of the particle $= mass\times(speed \,of \,light)^2$
→
A magnet is suspended in the magnetic meridian with an untwisted wire. The upper end of wire is rotated through $180^o$ to deflect the magnet by $30^o$ from magnetic meridian. When this magnet is replaced by another magnet, the upper end of wire is rotated through $ 270^o$ to deflect the magnet $30^o$ from magnetic meridian. The ratio of magnetic moments of magnets is
→
The near point of a person is $75 \,cm$. In order that he may be able to read book at a distance $30\,cm$. The power of spectacles lenses should be
→
In an experiment to find $emf$ of a cell using potentiometer, the length of null point for a cell of emf $1.5\,V$ is found to be $60\,cm$. If this cell is replaced by another cell of $emf\; E$. the length-of null point increases by $40\,cm$. The value of $E$ is $\frac{x}{10} V$. The value of $x$ is $............$
→