MCQ
Missing lines in a continuous spectrum reveal
  • A
     Defects of the observing instrument
  • B
     Absence of some elements in the light source
  • C
    Presence in the light source of hot vapours of some elements
  • Presence of cool vapours of some elements around the light source

Answer

Correct option: D.
Presence of cool vapours of some elements around the light source
Presence of cool vapours of some elements around the light source

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

Similar questions

Consider a hypothetical annihilation of a stationary electron with a stationary positron. What is the wavelength of resulting radiation.

($h =$ Plank’s constant, $c =$ speed of light, $m_0 =$ rest mass)

Electromagnetic waves
Two sources of equal $emf$ are connected to an external resistance $R$. The internal resistances of the two sources are ${R_1}$ and ${R_2}\,({R_2} > {R_1})$. If the potential difference across the source having internal resistance ${R_2}$ is zero, then
Which of the following is true for number of spectral lines in going form Layman series to Pfund series
A thick plane mirror shows a number of images of the filament of an electric bulb. Of these, the brightest image is the
Ratio between total intensity of magnetic field at equator to poles is
A proton is accelerated through $50,000\, V$. Its energy will increase by
$(A)$ Line spectra is due to atoms in gaseous state:
$(B)$ Band spectra is due to molecules:
In a Young’s double slit experimental arrangement shown here, if a mica sheet of thickness $t$ and refractive index $\mu $ is placed in front of the slit ${S_1},$ then the path difference $({S_1}P - {S_2}P)$
The current in flowing along the path $A B C D$ of a cube (shown in the left figure) produces a magnetic field at the centre of cube of magnitude $B$. Dashed line depicts the non-conducting part of the cube. Consider a cubical shape shown to the right which is identical in size and shape to the left. If the same current now flows in along the path $D A E F G C D$, then the magnitude of magnetic field at the centre will be