NEET2016PhysicsWave OpticsActual
In a Fraunhofer diffraction at single slit of width d with incident light of wavelength 5500 Å , the first minimum is observed, at angle 30^ . The first secondary maximum is observed at an angle =
Options
- A⁻¹ 1 2
- B⁻¹ 1 4
- C⁻¹ 3 4
- D⁻¹ 3 2
Correct answer
C. ⁻¹ 3 4
Step-by-step solution
Slit width =d =5500 Å=5.5 10⁻⁷ ~m , _n=30^ For first secondary minima, d _n= = _n = 5.5 10⁻⁷ 30^ =11 10⁻⁷ ~m For first secondary maxima, d _n= 3 2 i. e. _n= 3 2 d = 3 5.5 10⁻⁷ 2 11 10⁻⁷ _n= 3 4 or _n= ⁻¹(3 / 4)