A diffraction pattern is observed using a beam of red light. What will happen if the red light is replaced by the blue light?

A beam of light of \(\lambda = 600~\text{nm}\) from a distant source falls on a single slit \(1~\text{mm}\) wide and the resulting diffraction pattern is observed on a screen \(2~\text{m}\) away. The distance between the first dark fringes on either side of the central bright fringe is:
1. \(1.2~\text{cm}\)
2. \(1.2~\text{mm}\)
3. \(2.4~\text{cm}\)
4. \(2.4~\text{mm}\)

For a parallel beam of monochromatic light of wavelength \(\lambda\), diffraction is produced by a single slit whose width \(a\) is much greater than the wavelength of the light. If \(D\) is the distance of the screen from the slit, the width of the central maxima will be:

The first diffraction minima due to a single slit diffraction is at \(\theta = 30^{\circ}\) for a light of wavelength  \(5000~\mathring {A}.\)  The width of the slit is:
1. \(5\times 10^{-5}~\text{cm}\)
2. \(10\times 10^{-5}~\text{cm}\)
3. \(2.5\times 10^{-5}~\text{cm}\)
4. \(1.25\times 10^{-5}~\text{cm}\)

What will be the angular width of central maxima in Fraunhofer diffraction when the light of wavelength \(6000~\mathring {A}\) is used and slit width is \(12\times 10^{-5}~\text{cm}\)$$?
1. \(2~\text{rad}\)
2. \(3~\text{rad}\)
3. \(1~\text{rad}\)
4. \(8~\text{rad}\)

A linear aperture whose width is \(0.02\) cm is placed immediately in front of a lens of focal length \(60\) cm. The aperture is illuminated normally by a parallel beam of wavelength \(5\times 10^{-5}\) cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is:

The angular width of the central maximum in the Fraunhofer diffraction for \(\lambda=6000~{\mathring{A}}\) is \(\theta_0\). When the same slit is illuminated by another monochromatic light, the angular width decreases by \(30\%\). The wavelength of this light is: