The focal length of the objective of an astronomical telescope is 1 m and it is in normal adjustment. Initially the telescope is focussed to a heavenly body. If the same telescope is to be focussed to an object at a distance of 21 m from the objective, then identify the correct choice

The focal length of the objective of an astronomical telescope is 1 m

1.	The focal length of the objective of an astronomical telescope is 1 m and it is in normal adjustment. Initially the telescope is focussed to a heavenly body. If the same telescope is to be focussed to an object at a distance of 21 m from the objective, then identify the correct choice
Answer» eye piece should be displaced by 2 CM away from the objective eye piece should be displaced by 2 cm towards the objective eye piece should be displaced by 5 cm towards from the objective eye piece should be displaced by 5 cm away from the objective Solution :`u_(1)=oo,v_(1)=f_(0)=1M` `u_(2)=21M, 1/F=1/v_(2)-1/u_(2)implies` find`v_(2)`

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The focal length of the objective of an astronomical telescope is 1 m and it is in normal adjustment. Initially the telescope is focussed to a heavenly body. If the same telescope is to be focussed to an object at a distance of 21 m from the objective, then identify the correct choice

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