Answer:
14869817.395 m
Explanation:
=22 microarcsecond
λ = Wavelength = 1.3 mm
Converting to radians we get
From Rayleigh Criterion
Diameter of the effective primary objective is 14869817.395 m
It is not possible to build one telescope with a diameter of 14869817.395 m. But, we need this type of telescope. So, astronomers use an array of radio telescopes to achieve a virtual diameter in order to observe objects that are the size of supermassive black hole's event horizon.