A) 1.5
B) 3.0
C) ? 15.0
D) + 15.0
Correct Answer: D
Solution :
\[u=-10\ cm,\ \ v=20\ cm\] \[\frac{1}{f}=\frac{1}{v}-\frac{1}{u}=\frac{1}{20}-\left( -\frac{1}{10} \right)=\frac{3}{20}\Rightarrow f=\frac{20}{3}\ cm\] Now \[P=\frac{100}{f}=\frac{100}{20/3}=+\ 15\ D\]You need to login to perform this action.
You will be redirected in
3 sec