Question

Power of the lens is -40 its focal length is *​

Answer 1

Answer:

$we \: know \: that \\ power = \frac{1}{focal \: length} \\ p = \frac{1}{f} \\ if \: power \: of \: lens \: is \: - 40 \: then \\ - 40 = \frac{1}{f} \\ f = \frac{1}{ - 40} \\ = - 0.025$