Answer
larger
Work Step by Step
If the lamp were switched from blue light to red light, you would be dealing with light of a longer wavelength. We can look at equation (36-12), diffraction of a circular aperture, to see how wavelength affects distance.
$\sin \theta= 1.22 \frac{\lambda}{d}$ (first minimum—circular aperture).
We can see that as the wavelength, $\lambda$, gets larger, the distance, d, must also get larger.
