Question

For small angles, what is the approximate path difference at a point a distance \(x\) from the central bright fringe?

Options

• \[\Delta=\frac{Dx}{d}\]

• \[\Delta=\frac{dx}{D}\]

• \[\Delta=\frac{x}{dD}\]

• \[\Delta=\frac{dD}{x}\]

Answer 1

For small angles, the path difference depends on slit separation \(d\), screen distance \(D\), and position \(x\). The approximation is \[\Delta=\frac{dx}{D}\].