Q19. A compound microscope’s real intermediate image lies 4 cm in front of an eyepiece of focal length 5 cm. The final image is:
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Question

Q19. A compound microscope’s real intermediate image lies 4 cm in front of an eyepiece of focal length 5 cm. The final image is:

G1 Physics · Accepted Answer

GIVEN: Eyepiece is a convex lens of focal length +5 cm; real intermediate image acts as its object 4 cm to the left. Step 1: For eyepiece, uₑ = −4 cm and fₑ = +5 cm. Step 2: Lens formula: 1/fₑ = 1/vₑ − 1/uₑ ⇒ 1/5 = 1/vₑ + 1/4. Step 3: 1/vₑ = 1/5 − 1/4 = (4 − 5)/20 = −1/20. Step 4: vₑ = −20 cm. Negative image distance means image is virtual and lies in front of the eyepiece. FINAL ANSWER: Virtual image, 20 cm from eyepiece. Option B.