A thin convex lens of power 5D is kept in contact with a thin concave lens of power 8D. Calculate…
A thin convex lens of power 5D is kept in contact with a thin concave lens of power 8D. Calculate the focal length of the combination.
Answer
Answer
AIWritten by AI - it can contain mistakes.
Power of the convex lens, $P_1 = +5\text{ D}$
Power of the concave lens, $P_2 = -8\text{ D}$
Equivalent power of the combination:
$P = P_1 + P_2 = +5\text{ D} + (-8\text{ D}) = -3\text{ D}$
Focal length of the combination:
$F = \frac{1}{P} = \frac{1}{-3\text{ D}} = -\frac{1}{3}\text{ m} \approx -0\cdot333\text{ m} = -33\cdot3\text{ cm}$
Final answer: -0.333 m
Final answer: -0.333 m
From ISC 2026 Physics Paper 1, question 1(B)(v).