Question

A 18.0 W LED light bulb is turned on. It has an operating voltage of 120 V.(a)How much current (in A) flows through the bulb? _________:A(b)What is the resistance (in Ω) of the bulb? _________:Ω(c)How much energy (in J) is used each second? _________:J each second

Answer 1

(a)

In order to calculate the current, we can use the formula below:

`\begin{gathered} P=I\cdot V\\ \\ 18=I\cdot120\\ \\ I=(18)/(120)=0.15\text{ A} \end{gathered}`

(b)

To calculate the resistance, we can use Ohm's Law:

(c)

Since the power of 18 W means 18 J of energy is consumed each second, so the energy used each second is 18 J.