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An LED is constructed from pn junction b...

An LED is constructed from pn junction based on a certain semi-conducting material whose energy gap is 1.9 eV.Then, the wavelength of the emitted light is:

A

`6.5 xx10^(-7) m`

B

`2.9 xx 10^(-9)m`

C

`9.1 xx 10^(-5) m`

D

`1.6 xx 10^(-8) m`

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