(A)OR(B)

Define the following terms in the context of a diverging mirror:

(i)

Principal focus

(ii)

Focal length Draw a labelled ray diagram to illustrate your answer.

\[\begin{aligned} & f=15 \mathrm{~cm}, \mathrm{u}=-25 \mathrm{~cm}, \mathrm{~h}=10 \mathrm{~cm} \\ & \frac{1}{\mathrm{v}}=\frac{1}{15 \mathrm{~cm}}+\frac{1}{-25 \mathrm{~cm}}=\frac{2}{75}=+\frac{1}{37 \cdot 5} \\ & v=37 \cdot 5 \mathrm{~cm} \end{aligned} \] \[\begin{aligned} & \text { height of the image }=\frac{v}{u} \times \text { height of the object } \\ & =\frac{37 \cdot 5}{-25 \mathrm{~cm}} \times 10 \mathrm{~cm} \end{aligned} \] h' = -$\displaystyle 15$ cm