Geometrical OpticsHard
Question
Diameter of a plano-convex lens is 6cm and thickness at the center is 3 mm. If speed of light in material of lens is 2 × 108 m/s, the focal length of the lens is :
Options
A.15 cm
B.20 cm
C.30 cm
D.10 cm
Solution
From trigonometry,
R2 = (3)2 + (R- 0.3)2
∴ from Lens-Maker formula,
f = 30cm
Create a free account to view solution
View Solution FreeMore Geometrical Optics Questions
When a pin is moved along the principle axis of a small concave mirror, the image position coincides with the object at ...A ray is incident at 30o angle on plane mirror. What will be deviation after reflection from mirror....The wavelength of light in two liquids ′x′ and ′y′ is 3500 and 7000 , then the critical angle wi...If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting. Calculate the focal le...The curve of angle of incidence versus angle of deviation shown has been plotted from prism. The value of refractive ind...