Answer :
Given:
n = 1.4
radius of the front = 1.3 m
radius of the rear = -0.9 m
Let's find the refractive power of the lens.
To find the refractive power of the lens, apply the formula:
[tex]\frac{1}{f}=(n-1)(\frac{1}{R_1}-\frac{1}{R_2})[/tex]Thus, we have:
[tex]\begin{gathered} \frac{1}{f}=(1.4-1)(\frac{1}{1.3}-(-\frac{1}{0.9})) \\ \\ \frac{1}{f}=(0.4)(\frac{1}{1.3}+\frac{1}{0.9}) \\ \\ \frac{1}{f}=(0.4)(\frac{0.9+1.3}{1.17}) \\ \\ \frac{1}{f}=(0.4)(\frac{2.2}{1.17}) \\ \\ \frac{1}{f}=0.75 \end{gathered}[/tex]Therefore, the refractive power of the lens is 0.75 diopters
• ANSWER
1. 0.75 diopters