(a(i))[1]
From Fig. 2.1, measure the length $x$ and the length $y$ to the nearest millimetre. $x$ = [BLANK] cm $y$ = [BLANK] cm
(a(ii))[1]
Fig. 2.1 is drawn at one quarter of full size. Determine the actual distance $u$ between the lens and the object and determine the actual distance $v$ between the lens and the screen. $u$ = [BLANK] cm $v$ = [BLANK] cm
(a(iii))[2]
Use the equation: $f = \frac{uv}{u + v}$ to calculate the focal length $f$ of the lens. Give your response to 2 significant figures. $f$ = [BLANK] cm
(b)[1]
The lens manufacturer says that the lens has focal length $f = 7.0\,\text{cm}$. Explain, with a reason, whether your results are consistent with the manufacturer’s value within the limits of experimental accuracy.