A) \[+1\text{ }D\]
B) \[-1\,D\]
C) zero
D) \[+\,0.5D\]
E) \[-\,0.5D\]
Correct Answer: E
Solution :
\[P={{P}_{1}}+{{P}_{2}}\] \[=\frac{100}{{{f}_{1}}}+\frac{100}{{{f}_{2}}},\]both\[{{f}_{1}}\]and\[{{f}_{2}}\]are in cm. \[=\frac{100}{50}-\frac{100}{40}\] \[=2-2.5=-0.5\,D\]You need to login to perform this action.
You will be redirected in
3 sec