In an Open Cluster, the Sizes of Some of the Lower-Mass

question 16

Multiple Choice

In an open cluster, the sizes of some of the lower-mass stars may have been limited when the surrounding material the stars were accreting was blown away by ultraviolet radiation. What is the source of this UV radiation?

• A) The radiation sweeps generally through the Galaxy.
• B) The radiation comes from supernova explosions outside the cluster.
• C) The more massive O and B stars in the cluster evolve more quickly and produce ultraviolet radiation, while the less massive stars are still evolving toward the main sequence.
• D) The ultraviolet radiation is emitted by the low-mass stars themselves when they begin hydrogen burning.

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Definitions:

Marginal Cost

The increase in total cost that arises from producing one additional unit of a product or service.

Economic Profit-Maximising

The point at which a firm achieves the highest profit possible given its production costs and market conditions.

Cost-Based Pricing

A pricing method used by companies to determine the selling price of a product by adding a profit margin to the total cost of producing or purchasing the product.

Standard Cost Analysis

The practice of comparing standard costs to actual costs to identify variances, understand causes, and take corrective actions.