For an L E D to emit light in visible region of the electromagnetic spectrum, it can have energy band gap in the range of, (Plank's constant, h=6.6 10⁻³⁴ Js and speed of light, e=3 10^8 ~ms ⁻¹ in vacuum)

Step-by-step solution

Key Idea Frequency of visible rays range from 4 10¹⁴ ~Hz to 7 10¹⁴ ~Hz . Maximum and minimum energy of photon in visible light, aligned E_ & =h v= 6.6 10⁻³⁴ 7 10¹⁴ 1.6 10⁻¹⁹ & =2.88 eV 3 eV E_ & = 6.6 10⁻³⁴ 4 10¹⁴ 1.6 10⁻¹⁹ & =1.65 eV 1.7 eV aligned So, the correct option matches between the energy 1.7 eV to 3 eV is ( c ) ,