Which Statement About Extrasolar Planets Found to Date Is TRUE

question 42

Multiple Choice

Which statement about extrasolar planets found to date is TRUE?

• A) All are terrestrials, comparable in size to Earth.
• B) Few are found by Doppler shifts of their stars, due to their gravity.
• C) All lie more than 2 AU from their star.
• D) Most have orbital periods of more than a year.
• E) Some are so close to their stars that their periods are just a few days.

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Definitions:

Extinction

In psychology, the gradual weakening and disappearance of a conditioned response when the conditioned stimulus is no longer paired with the unconditioned stimulus.

Variable-Ratio Schedule

A reinforcement schedule where a response is reinforced after an unpredictable number of responses, making it very resistant to extinction.

Fixed-Interval Schedule

A type of reinforcement schedule in operant conditioning where rewards are delivered at fixed time intervals, provided the correct response is made.

Stimulus Generalisation

The psychological phenomenon in which responses to a specific stimulus become triggered by stimuli that are similar in some way to the original stimulus.