An astronomical refracting telescope will have large angular magnification and high angular resolution when it has an objective lens with:
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Question

An astronomical refracting telescope will have large angular magnification and high angular resolution when it has an objective lens with:

G1 Physics · Accepted Answer

Step 1: Angular magnification M = fₒ/fₑ; increasing objective focal length raises magnification. Step 2: Resolution θₘᵢₙ ≈ 1.22λ/D; larger aperture reduces the minimum resolvable angle. Final answer: (A) large focal length and large aperture.