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A 100 watt lamp has a resistance of 120 Ω. Find the current in the lamp.Group of answer choices2.15 A1.20 A0.913 A0.833 A

1 Answer

5 votes

0.913 A

Step-by-step explanation

the poweris given by


P=I^2R

so

Step 1

Let


\begin{gathered} I=I \\ P=100\text{ watts} \\ \text{resistance}=120\text{ ohm} \end{gathered}

b) now replace


\begin{gathered} P=I^2R \\ 100=I^2\cdot120 \\ \text{divide boths sides by 120} \\ (100)/(120)=(I^2\cdot120)/(120) \\ 0.8333=I^2 \\ \text{square root in both sides} \\ √(0.8333)=√(I^2) \\ 0.91287=I \\ \text{rounded} \\ I=0.913\text{ Amperes} \end{gathered}

therefore, the answeris

0.913 A

I hope this helps you

User Cosmosis
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