Action of lenses (AQA A-Level Physics): Flashcards

Point where parallel rays converge or appear to diverge from

$\text{power} = \frac{1}{f}$ where $f$ is in metres

Dioptre (D) or $\text{m}^{-1}$

Positive

Ability of eye lens to change its focal length

Approximately 25 cm

$\frac{1}{f} = \frac{1}{u} + \frac{1}{v}$

Light rays actually pass through the image location

Rays appear to come from location but don't pass through it

$m = \frac{v}{u}$