A) 30 cm
B) 10 cm
C) 20 cm
D) 40 cm
Correct Answer: B
Solution :
[b] For telescope Tube length \[\left( L \right)={{f}_{o}}+{{f}_{e}}\] And magnification \[(m)=\frac{{{f}_{e}}}{{{f}_{o}}}\] Where \[{{f}_{o}}\] and \[{{f}_{e}}\]are focal length of objective And eyepiece \[\therefore {{f}_{o}}+{{f}_{e}}=60\] and \[{{f}_{e}}=5{{f}_{o}}\] \[\therefore {{f}_{o}}=50\text{ }cm\] \[{{f}_{e}}=10\text{ }cm\]You need to login to perform this action.
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