(a)[1]
Which separation is the focal length of the lens? Tick one box: C to $F_1$, O to C, $F_2$ to I, O to I.
(b)[3]
On Fig. 8.1, continue the two rays from the object arrowhead until each reaches the image position.
(c)[2]
State the effect, if any, that this has on the image’s position and size.