A student wishes to determine the separation between the slits of a double-slit plate…

PHYSICS · Subjective · CBSE · Physics · Wave Optics · Wave Optics

Problem

A student wishes to determine the separation between the slits of a double-slit plate supplied in the laboratory. The screen is fixed

2.0\,\text{m}

from the plate. She illuminates the slits with light of wavelength

632\,\text{nm}

and measures the distance between the

3^{\text{rd}}

bright fringe above the central maximum and the

7^{\text{th}}

bright fringe below it to be

11.4\,\text{mm}

. (i) Deduce the fringe width from this observation. (ii) Hence calculate the slit separation.