A) \[-280.0\text{ }cm\]
B) \[40.0\text{ }cm\]
C) \[21.5\text{ }cm\]
D) \[13.3\text{ }cm\]
Correct Answer: D
Solution :
For combination of lens \[\frac{1}{f}=\frac{1}{{{f}_{1}}}+\frac{1}{{{f}_{2}}}\] \[=(1.5-1)\,\left( \frac{1}{14}-\frac{1}{\infty } \right)\,+(1.2-1)\,\left( \frac{1}{\infty }\,-\frac{1}{-14} \right)\,=\frac{1}{20}\] \[\frac{1}{v}-\frac{1}{u}\,=\frac{1}{f}\] \[\frac{1}{v}\,-\frac{1}{40}\,=\frac{1}{20}\] \[V=\frac{40}{3}\,\,=13.3\,cm\]You need to login to perform this action.
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