A small light bulb is placed along the principal axis of a concave spherical mirror…
PHYSICS · Multi-part · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments
Problem
A small light bulb is placed along the principal axis of a concave spherical mirror whose center of curvature lies on a horizontal optical bench. The bulb is successively positioned at three different locations:
• Position I: 2.0 cm in front of the mirror, which is well inside the mirror’s focal length.
• Position II: 9.0 cm in front of the mirror, between the focal point and the center of curvature.
• Position III: 25 cm in front of the mirror, beyond the center of curvature.
For each position the resulting image is observed on a movable screen when possible.
(1) For Position I, describe whether the image is real or virtual, upright or inverted, and enlarged or reduced. Support your answer qualitatively with reference to the behavior of at least two principal rays.
(2) For Position II, describe each of the three image characteristics requested in part (a). Explain your reasoning.
(3) For Position III, answer the same three questions and justify your conclusions.
(4) Compare the orientations of the images in the three trials and explain how the relative location of the object with respect to the focal point determines those orientations.