Choose the correct answer/s.

1.) In an interference experiment, monochromatic light from alaser is passed through two parallel slits separated byd.  An interference pattern is formed on thescreen placed at a distance R from the screen. If theseparation distance between the slits is doubled, which of thefollowing is true?

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

2.)

Which of the following statements is NOT true about adouble-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-litpattern, which of the following is correct?

		There are more bright fringes in the double-slit patterncompared to the single-slit pattern.
		There are more dark fringes in the single-slit pattern comparedto the double-slit pattern.
		The dark fringes in the double-slit pattern are equally spacedwhile the dark fringes in the single-slit pattern are not equallyspaced.
		The bright fringes in the double-slit pattern are equally spacedwhile the dark fringes in the single-slit pattern are not equallyspaced.

8.)

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

		The central bright fringe is twice as long as the other brightfringes.
		The positions of dark fringes vary inversely with slit-screenseparation.
		The central bright fringe and the other bright fringes have thesame brightness / intensity.
		The positions of the dark fringes vary directly with theslit-width.