Chapter 6, Problem 13STP

To determine

To Calculate: The electrical energy converted by the given circuit.

Answer to Problem 13STP

The electrical energy converted by the given circuit is $\underset{\_}{0.03\text{ kWh}}$ .

Explanation of Solution

Given data:

Current in the circuit, $I=1.0\text{ A}$

Time, $t=2.5\text{ h}$

Voltage difference across the circuit, $V=12\text{ V}$

Formula used:

• Electrical Power Equation:

  $P=IV$

Where, $P$ is the power of a device in watts, $I$ is the current through the device in amperes, and $V$ is the voltage difference across the device in volts.

• Electrical Energy Equation:

  $E=Pt$

Where $E$ is the electrical energy provided by the power company in kilowatt-hours, $P$ is the power of an appliance in kilowatts, and $t$ is time in hours for which the energy is provided.

Calculation:

Substitute the values of voltage difference and current in the electrical power equation to get power:

  $\begin{array}{l}P=IV\\ P=(1.0\text{ A)(12 V)}\\ P=12\text{W}\\ P=0.012\text{kW}\end{array}$

Now, to find electrical energy, substitute the values of power (calculated above) and time in the electrical energy equation:

  $\begin{array}{l}E=Pt\\ E=(0.012\text{ kW)(2}\text{.5 h)}\\ E=0.03\text{kWh}\end{array}$

Conclusion:

The electrical energy converted by the given circuit is $\underset{\_}{0.03\text{ kWh}}$ .