A student places a small candle 12 cm in front of a thin concave lens of focal length…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Geometric Optics · Geometric Optics
Problem
A student places a small candle 12 cm in front of a thin concave lens of focal length 20 cm. After completing the calculations, the student tries to project the image onto a screen situated anywhere behind the lens but cannot obtain a visible image. Which of the following best explains why the image cannot be captured on the screen?
(a) The image is real and located 7.5cm behind the lens; the student needs to place the screen at that distance to see it.
(b) Because the candle is closer than twice the focal length, the lens is too weak to produce an image that can reach the screen.
(c) The image is virtual and forms on the same side as the candle, so it cannot be captured on a screen.
(d) The lens forms an upright image, and upright images cannot be projected onto a screen.