Q18. An objective with focal length 1 cm forms a real intermediate image 16 cm from the objective. An eyepiece with focal length 4 cm produces the final image at D = 25 cm. The total angular magnification magnitude is:
Options

Question

Q18. An objective with focal length 1 cm forms a real intermediate image 16 cm from the objective. An eyepiece with focal length 4 cm produces the final image at D = 25 cm. The total angular magnification magnitude is:

Options

G1 Physics · Accepted Answer

GIVEN: Objective fₒ = 1 cm; real intermediate image at vₒ = 16 cm; eyepiece fₑ = 4 cm; D = 25 cm; final image at near point. Step 1: Objective magnification magnitude |mₒ| = vₒ/fₒ − 1 = 16/1 − 1 = 15. Step 2: Eyepiece near-point magnification = 1 + D/fₑ = 1 + 25/4 = 1 + 6.25 = 7.25. Step 3: Total angular magnification |M| = |mₒ| × mₑ = 15 × 7.25. Step 4: 15 × 7.25 = 108.75. FINAL ANSWER: 108.75. Option B.