Question

Choose the correct answer/s.

1.) In an interference experiment, monochromatic light from a laser is passed through two parallel slits separated by d.  An interference pattern is formed on the screen placed at a distance R from the screen. If the separation distance between the slits is doubled, which of the following is true?

		The distance of a particular dark fringe from the central bright fringe will be doubled.
		The wavelength of light will be doubled.
		The distance of a particular bright fringe from the central bright fringes will be doubled.
		The length of the central bright fringe will be halved.

2.)

Which of the following statements is NOT true about a double-slit interference pattern?

		The bright fringes are longer than the dark fringes.
		Adjacent bright fringes have approximately equal brightness / intensity.
		The dark fringes are equally-spaced.
		The bright fringes are equally spaced.

3.)

If you compare the single-slit pattern and the double-lit pattern, which of the following is correct?

		There are more bright fringes in the double-slit pattern compared to the single-slit pattern.
		There are more dark fringes in the single-slit pattern compared to the double-slit pattern.
		The dark fringes in the double-slit pattern are equally spaced while the dark fringes in the single-slit pattern are not equally spaced.
		The bright fringes in the double-slit pattern are equally spaced while the dark fringes in the single-slit pattern are not equally spaced.

8.)

In a diffraction experiment, monochromatic light from a laser is passed through a slit of width a.  A diffraction pattern is formed on the screen placed at a distance x from the screen. Which of the following statements is true?

		The central bright fringe is twice as long as the other bright fringes.
		The positions of dark fringes vary inversely with slit-screen separation.
		The central bright fringe and the other bright fringes have the same brightness / intensity.
		The positions of the dark fringes vary directly with the slit-width.

Answer 1