Q41E
Question
The VLBA (Very Long Baseline Array) uses a number of individual radio telescopes to make one unit having an equivalent diameter of about 8000 km. When this radio telescope is focusing radio waves of wavelength 2.0 cm, what would have to be the diameter of the mirror of a visible-light telescope focusing the light of wavelength 550 nm so that the visible-light telescope has the same resolution as the radio telescope?
Step-by-Step Solution
VerifiedThe diameter of the mirror of a visible-light telescope is 220m.
According to the Rayleigh criterion for the diffraction limit to resolution, two images are only resolvable when the center of one's diffraction pattern is directly over the first minimum of the other's diffraction pattern.
Using the Rayleigh’s criterion, in both cases the setups have the same resolving power;
On putting the values;
Hence, the diameter of the mirror of a visible-light telescope is 220m.