JEE Main 2014 · 12 Apr · Shift 1 · Physics Q28

PhysicsSingle correct+4 / -1Question 28 of 90

For LED's to emit light in visible region of electromagnetic light, it should have energy band gap in the range of :

0.1 eV to 0.4 eV

0.5 eV to 0.8 eV

0.9 eV to 1.6 eV

1.7 eV to 3.0 eV

Answer and worked solution

Official answer: D

Visible photons span about 400-700 nm, i.e. about 1.8-3.1 eV. So the band gap should be about 1.7 eV to 3.0 eV.

JEE Main 2014 · 12 Apr · Shift 1, Physics question 28