Answer:
a). [tex]V=\frac{U.F}{U-F}[/tex]
b). V = 15 units
Step-by-step explanation:
Focal length F of a lens made by combining two lenses of different focal lengths U and V will be,
[tex]\frac{1}{F}=\frac{1}{U}+\frac{1}{V}[/tex]
A). By solving the given formula,
[tex]\frac{1}{V}=\frac{1}{F}-\frac{1}{U}[/tex]
[tex]\frac{1}{V}=\frac{U-F}{U.F}[/tex]
[tex]V=\frac{U.F}{U-F}[/tex]
B). If F = 6 and U = 10 then we have to find the value of V.
By substituting the given values in the formula,
[tex]V=\frac{6\times 10}{10-6}[/tex]
[tex]V=\frac{60}{4}[/tex]
V = 15 units
Therefore, focal length (V) of the lens = 15 units