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Physics
Physics
Problem
A lens is placed between a source of light and a wall. It forms images of area A1 and A2 on the wall, for its two different positions. The area of the source of light is: (a)
A
1
A
2
\sqrt{A_1 A_2}
A
1
A
2
(b)
A
1
+
A
2
2
\frac{A_1 + A_2}{2}
2
A
1
+
A
2
(c)
(
A
1
+
A
2
2
)
2
\left(\frac{\sqrt{A_1} + \sqrt{A_2}}{2}\right)^2
(
2
A
1
+
A
2
)
2
(d) None
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