Chapter 24, Problem 19Q

(a)

To determine

To explain: The advantage of the many slits for diffraction grating.

Answer to Problem 19Q

Using many slits for diffraction grating, will increase interference.

Explanation of Solution

Introduction: The pattern resulting from superimposing of two waves is known as interference. Interference can be destructive or constructive. The separation of polychromatic light into its constituent wavelength is termed as diffraction grafting.

Destructive interference occurs after the crest of a wave overlaps the trough of another wave. The waves destructively interfere and also, cancel each other, once crest of one & trough of other interfere.

Diffraction gratings are employed to make accurate measurements of wavelength of light. According to this, advantage of having several slits in diffraction grating is that this makes bright maxima in interference pattern sharply defined, narrower and brighter.

(b)

To determine

To explain: The advantage of closely spaced slits for diffraction grating.

Answer to Problem 19Q

The closely packed slits diffracted the light at larger angle and measurement can be very easy.

Explanation of Solution

Introduction: The pattern resulting from superimposing of two waves is known as interference. Interference can be destructive or constructive. The separation of polychromatic light into its constituent wavelength is termed as diffraction grafting.

Destructive interference occurs after the crest of a wave overlaps the trough of another wave. The waves destructively interfere and also, cancel each other, once crest of one & trough of other interfere.

Diffraction gratings are employed to make accurate measurements of wavelength of light. According to this, advantage of having tightly spaced slits in the diffraction grating is that this spreads out bright maxima in interference pattern and also, makes them easier to measure.