Converging lens: object inside the focal length
An object is 10 cm from a converging lens with a focal length of 15 cm. What image forms?
Answer D: explanation for every choice
A
6 cm comes from adding 1/f and 1/o instead of subtracting.
B
A virtual image from a converging lens is magnified, not reduced.
C
This drops the negative sign. A negative image distance means a virtual image.
D
Correct. 1/i = 1/15 − 1/10 = −1/30, so i = −30 cm (virtual), and m = −i/o = +3.
TakeawayObject inside f of a converging lens → virtual, upright, magnified (a magnifying glass).
Equation usedThin lens and mirror equation
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