Power of combination of two concave …

The power of a combination of two concave lenses can be determined using the lens formula and the power formula for lenses. When lenses are in contact (i.e., their curved surfaces are facing each other), the formula to calculate their combined power is: $$P_{\text{total}} = P_1 + P_2$$ Where: - $P_{\text{total}}$ is the total power of the combination of lenses. - $P_1$ is the power of the first lens. - $P_2$ is the power of the second lens. The power $P$ of a lens is given by: $$P = \frac{1}{f}$$ Where: - $P$ is the power of the lens. - $f$ is the focal length of the lens. If you have two concave lenses with focal lengths $f_1$ and $f_2$, you can calculate their individual powers as $P_1 = \frac{1}{f_1}$ and $P_2 = \frac{1}{f_2}$, respectively. Then, you can find the total power by adding these individual powers. So, to calculate the total power of a combination of two concave lenses, simply add their individual powers using the formula $P_{\text{total}} = P_1 + P_2$. This is applicable when the lenses are in contact. If they are separated by a distance, you would need to consider the separation between the lenses when calculating their combined power.

1/f1+1/f2=1/F