Lens-Maker's Formula: a Compound Lens Is Made by Joining the Plane

question 91

Multiple Choice

Lens-maker's formula: A compound lens is made by joining the plane surfaces of two thin plano-convex lenses of different glasses. The radius of curvature of each convex surface is 80 cm. The indices of refraction of the two glasses are 1.50 and 1.60. What is the focal length of the compound lens?

• A) 67 cm
• B) 69 cm
• C) 71 cm
• D) 73 cm
• E) 75cm

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Definitions:

Opportunity Cost

The value of the best alternative forgone when a choice is made between different options.

Tax Rate

The percentage at which an individual or corporation is taxed by the government on income or profits.

Market Value

The present rate at which a service or asset is available for purchase or sale on the open market.

Straight Line

A depreciation method where an asset loses value evenly across its useful life.