A) \[-\,4.8\,cm,\ -\,3.3\,D\]
B) \[-\,5.8\,cm,\ -\,4.3\,D\]
C) \[-\,7.5\,cm,\ -\,6.3\,D\]
D) \[-\,15.8\,cm,\ -\,6.3\,D\]
Correct Answer: D
Solution :
\[v=-15cm,\] \[u=-\,300cm,\] From lens formula \[\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\] \[\Rightarrow \frac{1}{f}=\frac{1}{-15}-\frac{1}{-300}=\frac{-19}{300}\]\[\Rightarrow f=\frac{-\,300}{19}=-\,15.8\,cm\] and power \[P=\frac{100}{f}cm\]\[=\frac{-100\times 19}{300}\]= ? 6.33 D.You need to login to perform this action.
You will be redirected in
3 sec