JEE MAIN - Physics (2022 - 25th July Morning Shift - No. 28)
The energy band gap of semiconducting material to produce violet (wavelength = 4000$$\mathop A\limits^o $$ ) LED is ______________ $$\mathrm{eV}$$. (Round off to the nearest integer).
پاسخ دهید
3
توضیح
Energy corresponding to wavelength 4000 $$\mathop A\limits^o $$
$$E = {{hc} \over \pi }$$
$$ = {{6.6 \times {{10}^{ - 34}} \times 3 \times {{10}^8}} \over {4000 \times {{10}^{ - 10}} \times 1.6 \times {{10}^{ - 19}}}}$$ eV
$$ = {{12400} \over {4000}}$$
$$=3.1$$ eV
$$\approx$$ 3 eV