# How does distance affect diffraction grating?

Table of Contents

- 1 How does distance affect diffraction grating?
- 2 What happen when the number of ruling N lines in grating is made larger?
- 3 What happens to the order of spectrum if the distance between the particle and the screen is increased?
- 4 How would the diffraction pattern change if the slits are farther apart?
- 5 What is the advantage of increasing the number of lines in grating?
- 6 What happens when distance between slits is increased?
- 7 Which order of spectrum will be absent for diffraction grating if opaque space is equal to twice the width of transmission space?
- 8 What effect does the distance between the slit and the screen have on the interference pattern?
- 9 How to measure line spacing of a diffraction grating?
- 10 What is the difference between double slit experiment and diffraction grating experiment?

## How does distance affect diffraction grating?

If we move the screen farther from the double slit, the screen will intercept the light from the grating after the bright lines in the pattern have been able to spread out farther, increasing the distance between the bright spots on the screen.

## What happen when the number of ruling N lines in grating is made larger?

i) with the increase in number of lines the secondary maxima relative to the principal maxima decreases and becomes negligible. The principal maxima become more sharp and intense. Thus, a theoretical limit is reached the first order maximum will not be visible.

**What happens when you increase the distance between slits in a diffraction grating?**

If the distance between slits is increased far enough you get something like a picket fence, and the diffraction pattern would be like the shadow of a picket fence. What happens in between is that as the spacing is increased the bands get closer together and eventually merge to form an image of the grating.

### What happens to the order of spectrum if the distance between the particle and the screen is increased?

If the line spacing is large compared to the wavelength, the light will be diffracted into multiple orders. Each order is is diffracted at a larger order then the previous order. If the line spacing is small compared to the wavelength, only the zero order will reflect. There is no diffraction.

### How would the diffraction pattern change if the slits are farther apart?

If your slits are further apart, the light waves will be coming from spots that are further apart. That means that their path lengths will be more different from one another, giving bright spots that are closer together.

**What happens to the distance between maxima when a grating with more number of lines per grating is used?**

Diffraction gratings are often identified by the number of lines per centimeter; gratings with more lines per centimeter are usually more useful because the greater the number of lines, the smaller the distance between the lines, and the greater the separation of images on the screen.

#### What is the advantage of increasing the number of lines in grating?

Advantages of increasing the number of lines in the grating are: a The number of principle maxima that can be seen on a screen increase. b The distance between two adjacent principle maxima increases.

#### What happens when distance between slits is increased?

If the slit separation is increased then the separation of the interference fringes decreases. If the slit separation is large compared with the slit width then the diffraction patterns from the two slits can be resolved as shown in the diagram below.

**What is the relation between the dispersive powers of a grating and the order N of a spectrum?**

What is the relation between the dispersive power, D, of a grating and the order, n, of a spectrum? Thus, as we can see D ∝ n. Hence, higher the order, higher is the dispersive power.

## Which order of spectrum will be absent for diffraction grating if opaque space is equal to twice the width of transmission space?

These are known as missing order spectrum or absent spectra. The above equation 3 is the condition for the spectrum of the order n to be missing or absent. Hence, when width of slit and opaque space in the grating are equal, then 2nd, 4th, 6th… order spectra are missing.

## What effect does the distance between the slit and the screen have on the interference pattern?

More interference occurs when d is wider. The spacings between different fringes decreases as the distance between the slits increases because it is dependent on L. Increasing the wavelength of the light increases the spacing between different fringes since the spacing between different fringes is wavelength dependent.

**What is the significance of diffraction grating in spectrophotometry?**

Significance The large distance between the red and violet ends of the rainbow produced from the white light indicates the potential this diffraction grating has as a spectroscopic tool. The more it can spread out the wavelengths (greater dispersion), the more detail can be seen in a spectrum.

### How to measure line spacing of a diffraction grating?

Check Your Understanding If the line spacing of a diffraction grating d is not precisely known, we can use a light source with a well-determined wavelength to measure it. Suppose the first-order constructive fringe of the emission line of hydrogen is measured at using a spectrometer with a diffraction grating.

### What is the difference between double slit experiment and diffraction grating experiment?

One difference between the interference of many slits (diffraction grating) and double slit experiment is that a diffraction grating makes a number of principle maxima along with lower intensity maxima in between. The

**How does the number of grating lines affect chromatic resolving power?**

The chromatic resolving power is directly proportional to the total number of grating lines. Increasing the total number of slits (whilst keeping the slit spacing constant) will produce brighter and narrower maxima.