Question

A light bulb consumes 150 J of electrical energy per second but only emits 15 J of light energy per second. Calculate the efficiency of the bulb.​

Answer 1

10% efficiency

Step-by-step explanation:

Formula for efficiency :

⇒ Efficiency (η) = Output energy (E₂) / Input energy (E₁)

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Given :

⇒ Input Energy (E₁) = 150 J

⇒ Output Energy (E₂) = 15 J

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Solving :

⇒ η = 15/150

⇒ η = 1/10

⇒ η = 10% efficiency