Advertisements
Advertisements
प्रश्न
The focal length of a concave lens is 10 cm. Calculate its power.
संख्यात्मक
Advertisements
उत्तर
As the lens is concave, its focal length is negative.
Focal length of the concave lens (f) = −10 cm [f for concave lens is −ive]
\[ \text{Applying, } \mathrm{P} = \frac{100}{f \text{(in cm)}} \]
\[ \Rightarrow \mathrm{P} = \frac{100}{-10} \]
\[ \Rightarrow \mathrm{P} = - \ 10 \ \text{D} \]
Minus sign indicates that the lens is concave in nature.
shaalaa.com
या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
