Which laboratory measurement requires index correction?

Question

G1 Physics · Accepted Answer

Step 1: A lens or object holder on an optical bench has an index mark whose position may not exactly coincide with the holder's true optical reference plane. Step 2: This causes a systematic offset in measured object or image distances. Step 3: Index correction compensates for that holder/index offset in optical-bench measurements. Step 4: Resonance-tube measurements instead commonly require end correction, which is different. Final answer: Measurement of focal length using an optical bench (Op…