Electronics and Communication Engineering - Electronic Devices and Circuits - Discussion

Discussion Forum : Electronic Devices and Circuits - Section 1 (Q.No. 32)
32.
A particular green LED emits light of wavelength 5490, Å, the energy bandgap of the semiconductor material used there is .. h = 6.6 x 10-34 J sec.
2.26 eV
1.98 eV
1.17 eV
0.74 eV
Answer: Option
Explanation:

From Plank equation joule

to convert it into electron volt it will be divided by 1.6 x 10-19.

Discussion:
9 comments Page 1 of 1.

Jaya Nandhini said:   1 decade ago
E = ((6.6*10^-340*(3*10^8))/5490*10^-10.

= 3.6065*10^-19 J.
= 3.6065*10^-19/1.6 x 10-19 eV.
= 2.26 eV.
(4)

Karthik said:   9 years ago
Here c value is not given how you take the c = 3 x 10^8?

Nayana said:   9 years ago
c = speed of light.
(1)

Amit said:   9 years ago
@Jaya Nandhini.

Why 5490 multiplied by 10*10^-10?

Shifa said:   9 years ago
@Amit, wavelength is in Angstrom.

Sathishkumar.s said:   9 years ago
1 angstrom = 10^-10m.

Ashy said:   7 years ago
Thank you for the explanation.

Sireesha said:   7 years ago
Thanks @Sathis.

Santhosh said:   5 years ago
Thanks for explaining @Jaya Nandhini.

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