For a Pair of Stars to Be Classified as an Optical

question 212

Multiple Choice

For a pair of stars to be classified as an optical double,which condition must be TRUE?

• A) The stars must lie in almost the same direction from Earth but must not be orbiting around each other.
• B) The stars must be orbiting around each other, and one must periodically cross in front of the other (i.e., it must eclipse the other) as seen from Earth.
• C) The stars must be orbiting around each other, and absorption or emission lines from both stars must be visible in the spectrum.
• D) The stars must be orbiting around each other, and both stars must be visible through telescopes from Earth.

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Definitions:

Price of Steel

The price of steel is the cost for a specific weight or quantity of steel, a crucial material in construction, manufacturing, and infrastructure projects, influenced by factors such as market demand, production costs, and global economic conditions.

Equilibrium Price

The price at which the quantity of a good or service demanded by consumers equals the quantity supplied by producers, resulting in a stable market condition without surplus or shortage.

Equilibrium Quantity

The quantity of goods or services that is supplied and demanded at the equilibrium price, where the amount sellers are willing to sell equals the amount buyers are willing to buy.

Supply Curve Shift

A change in the position of the supply curve, either to the left or right, indicating a change in the quantity supplied at every price level, due to factors other than price.