Question

The radius of the curvature is 20cm find the focal length

Answer 1

HOLA

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Given , R = 20 cm

R = 2f

$f \: = \: \frac{r}{2} \: \: f \: = \: \frac{20}{2} \: = \frac{10}{1}$


f = 10cm

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HOPE U UNDERSTAND ☺☺☺

Answer 2

HEY!!

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▶️R= 20cm

▶️f= ? 

▶️R = 2f 

▶️R/2 = f 

▶️20/2 = f 

➡️➡️f = 10cm