Yuting (Sam)'s answer to Kc's Primary 6 Science Singapore question.
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Use method of elimination for the choices
A - No mention of timing of light bulbs X & Y
B - Same energy for X & Y. Purpose is to generate light with same amount of energy. Hence Y more energy efficient as more light energy produced.
C - same energy use. Light is wanted energy. Heat is unwanted energy. Hence X produce more unwanted energy than Y.
D - X generate more heat energy than Y
Ans : B, C, D.
A - No mention of timing of light bulbs X & Y
B - Same energy for X & Y. Purpose is to generate light with same amount of energy. Hence Y more energy efficient as more light energy produced.
C - same energy use. Light is wanted energy. Heat is unwanted energy. Hence X produce more unwanted energy than Y.
D - X generate more heat energy than Y
Ans : B, C, D.
Date Posted:
4 years ago
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