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A laser (light amplification by stimulat...

A laser (light amplification by stimulated emission of radiation) provides a coherent (in phase )nearly monochromatic source of high intensityi light. Lasers are used in eye surger, CD/DVD players basic research etc. some miodern eye lasers can be tuned to emit a desired wavelength. The following table shows the `lamda(nm),v(s^(-1))` and E(J) but some of the data is missing.

If an electrons absorbs energy equalto D in hydrogen atom in first excited state and after reaching highest excited level it returns to ground level. How many possible lines will be obtained in hydrogen spectrum?

A

10

B

6

C

3

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
B
(D)`=E=(hc)/(lamda)`
`=(6.63xx10^(-34)xx3xx10^(8))/(4.879xx10^(-7))`
(D)`=4.1xx10^(-19)`
In eV `4.1xx10^(-19)=2.55eV`
The e is already present at first excited level. So, by absorbign this much energy e can move up to fourth level and when it returns to ground level total lines will be `(n(n-1))/2=6`
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