(b) Compare the wavelength of the resultant wave with that of the component waves.

State how the diffracted pattern will change when:

(a) The wavelength of the incident wave is increased

State how the diffracted pattern will change when:

(b) The wavelength of the incident wave is decreased.

A constant frequency signal from a signal generator is fed to two loudspeakers placed $1.5 \mathrm{m}$ apart. A student, who is $8.0 \mathrm{m}$ away from the loudspeakers, walks across in a line parallel to the line between the loudspeakers. The student measures the distance between successive spots of loudness to be $1.2 \mathrm{m}$. Calculate:

(a) The wavelength of the sound

A constant frequency signal from a signal generator is fed to two loudspeakers placed $1.5 \mathrm{m}$ apart. A student, who is $8.0 \mathrm{m}$ away from the loudspeakers, walks across in a line parallel to the line between the loudspeakers. The student measures the distance between successive spots of loudness to be $1.2 \mathrm{m}$. Calculate:

(b) The frequency of the sound (assume the speed of sound is $330 \mathrm{m}{ \mathrm{s}}^{-1}$)

One of the spectral lines from a hydrogen discharge lamp has wavelength $656 \mathrm{nm}$. This light is incident normally at a diffraction grating with $5000$ lines ${\mathrm{cm}}^{-1}$.

Calculate the angles for the first- and second-order maxima for this light