The phenomenon that explains why light waves do not travel in a straight line is known as .......

$A$ diffraction pattern is obtained using a beam of red light. If red light is replaced by blue light,then:

$A$ screen is placed $50 \, cm$ from a single slit which is illuminated with $6000 \, \mathring{A}$. If the distance between the first and third minima in the diffraction pattern is $3 \, mm$,what is the width of the slit?

Light of wavelength $\lambda$ is incident on a slit of width $a$. The resulting diffraction pattern is observed on a screen placed at a distance $D$. If the linear width of the central maximum is equal to the width of the slit,then $D = $ . . . . . . .

In a diffraction pattern due to a single slit of width $a$,the first minimum is observed at an angle $30^{\circ}$ when light of wavelength $5000 \; \mathring{A}$ is incident on the slit. The first secondary maximum is observed at an angle of

The condition for obtaining secondary maxima in the diffraction pattern due to a single slit is: