The Reason That the Primary Mirror of an Astronomical Telescope

question 216

Multiple Choice

The reason that the primary mirror of an astronomical telescope is often shaped and polished to a parabolic shape is

• A) to avoid the chromatic aberration that would be produced by an equivalent spherical mirror.
• B) that it is lighter and easier to mount in a telescope because it requires less glass than an equivalent spherical mirror.
• C) that it is easier to produce, even though the resulting mirror will produce more spherical aberration than an equivalent spherical mirror.
• D) to avoid spherical aberration by bringing parallel rays to a single focus.

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Definitions:

Supply and Demand

Fundamental economic model that explains how the interaction between the quantity of a good or service available (supply) and the desire for it (demand) determines its price.

Consumers

Individuals or entities that purchase goods and services for personal use or consumption.

External Costs

Costs incurred as a result of an economic activity that affects third parties who did not choose to incur that cost.

Free Enterprise

An economic system where private businesses operate in competition, largely free of state control, with the prices of goods and services determined by the open market.