A) 11.67 cm
B) 12.67 cm
C) 13.00 cm
D) 12.00 cm
Correct Answer: A
Solution :
\[{{L}_{D}}={{v}_{o}}+{{u}_{e}}\] and for objective lens \[\frac{1}{{{f}_{o}}}=\frac{1}{{{v}_{o}}}-\frac{1}{{{u}_{o}}}\] Putting the values with proper sign convention. \[\frac{1}{+2.5}=\frac{1}{{{v}_{o}}}-\frac{1}{(-3.75)}\]\[\Rightarrow {{v}_{o}}=7.5\ cm\] For eye lens \[\frac{1}{{{f}_{e}}}=\frac{1}{{{v}_{e}}}-\frac{1}{{{u}_{e}}}\] \[\Rightarrow \frac{1}{+5}=\frac{1}{(-25)}-\frac{1}{{{u}_{e}}}\]\[\Rightarrow {{u}_{e}}=-\,4.16\ cm\] \[\Rightarrow \,|{{u}_{e}}|=4.16\ cm\] Hence \[{{L}_{D}}=7.5+4.16=11.67\ cm\]
You need to login to perform this action.
You will be redirected in
3 sec
