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Question:

An astronomical refracting telescope will have large angular magnification and high resolution, when it has an objective lens of: Small focal length and large diameter, Large focal length and large diameter, Small focal length and small diameter, Large focal length and small diameter

Small focal length and small diameter

Small focal length and large diameter

Large focal length and small diameter

Large focal length and large diameter

Solution:

Angular magnification = -fo/fe
Resolution∝D
Hence for an astronomical refracting telescope having larger focal length and larger diameter for large angular magnification and high resolution.