Line waves with wavelength $\lambda$ going through a slit with width a will be diffracted into circular waves with approximately equal amplitude in all forward directions
A) Always
B) Never
C) Only if $\lambda \gga$
D) Only if $a\lambda$
E) Only if $a=\lambda$

Question

Line waves with wavelength $\lambda$ going through a slit with width a will be diffracted into circular waves with approximately equal amplitude in all forward directions
A) Always
B) Never
C) Only if $\lambda \gg>a$
D) Only if $a>>\lambda$
E) Only if $a=\lambda$

Quizplus · Accepted Answer

When the wavelength $\lambda$ is much greater than the slit width $a$, the wave behaves like a point source, causing the waves to diffract widely in all forward directions.

Line Waves with Wavelength λ\lambdaλ Going Through a Slit with Width a Will Be Diffracted

Line Waves with Wavelength $\lambda$ Going Through a Slit with Width a Will Be Diffracted