MPSC Rajyaseva 2017 GS Paper 1 — Question 53
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ज्याच्या प्रत्येक पृष्ठभागाची वक्रता त्रिज्या 50 सेमी आहे, अशा डबल बहिर्वक्र भिंगाचे नाभीय अंतर किती असेल, जर काचेचा वकीभवन दर्शक 1.50 असेल ? What is the focal length of a double convex lens for which the radius of curvature of each surface is 50 cm and the refractive index of glass is 1.50 ?
1)100 सेमी / 100 cm
2)25 सेमी / 25 cm
3)50 सेमी / 50 cm✓ Correct
4)75 सेमी / 75 cm
Using the lens maker's formula 1/f = (n - 1)(1/R1 - 1/R2), with n = 1.50 and R1 = 50 cm, R2 = -50 cm, the focal length calculates to 50 cm.