JEE PYQ: Semiconductors Question 13
Question 13 - 2021 (26 Feb 2021 Shift 1)
LED is constructed from Ga-As-P semiconducting material. The energy gap of this LED is 1.9 eV. Calculate the wavelength of light emitted and its colour. [$h = 6.63 \times 10^{-34}$ Js and $c = 3 \times 10^8$ ms$^{-1}$]
(1) 654 nm and red colour
(2) 1046 nm and blue colour
(3) 1046 nm and red colour
(4) 654 nm and orange colour
Show Answer
Answer: (1)
Solution
$\lambda = 1240/1.9 = 652.63 \approx 654$ nm. Red light range is 620–750 nm.
BETA
