In diffraction,all fringes have .....

$A$ light ray of wavelength $\lambda$ is passing through a pinhole of diameter $D$ and the effect is observed on a screen placed at a distance $L$ from the pinhole. The approximations of geometrical optics are applicable, if

$A$ parallel monochromatic beam of light is incident normally on a narrow slit. $A$ diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first maximum of the diffraction pattern,the phase difference between the rays coming from the edges of the slit is

In a single-slit diffraction pattern,if the source of light is replaced by a source of shorter wavelength,the width of the central maximum will:

In a single slit diffraction experiment,for a wavelength of light $\lambda$,the half-angular width of the central maxima is $\theta$. For a wavelength of light $p\lambda$,the half-angular width of the central maxima is $q\theta$. What is the ratio of the half-angular widths of the first secondary maxima in the first case to the second case?

In an experiment, electrons are made to pass through a narrow slit of width '$d$' comparable to their de Broglie wavelength. They are detected on a screen at a distance '$D$' from the slit (see figure). Which of the following graphs can be expected to represent the number of electrons '$N$' detected as a function of the detector position '$y$' ($y = 0$ corresponds to the middle of the slit)?