Mini-Quiz: Black Holes

1. Why does the diameter of a star decrease when it runs out of fuel?

   It cools down, reducing any thermal expansionThat is correct. You are becoming a Champion in astronomy. Pressure from reflected light cause the decrease in sizeSorry, not correct. Try another button. In order to absorb more fuel from spaceGood try, but not right. Select another answer.

2. If the mass of a star was twice that of our Sun, what would be its event horizon radius if it became a Black Hole?

   About 3 kmSorry, not correct. Try another button. About 6 kmCorrect. Great job! No one is sure, because they can't see such a Black HoleOops! Wrong answer. Re-read the question and try again.

3. How are Black Holes sometimes detected?

   By shining a bright light into themOops! Wrong answer. Re-read the question and try again. There is no way to detect themGood try, but not right. Select another answer. By the effect they have on neighboring starsThat is correct. You are becoming a Champion in astronomy.

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