Question

A concave lens has:

Options

• Positive power (\[f > 0\])

• Positive power (\[f < 0\])

• Negative power (\[f > 0\])

• Negative power (\[f < 0\])

Answer 1

For a concave (diverging) lens the focal length is negative, \[f < 0\], and hence its power \[P = \frac{1}{f}\] is negative.