Question

A 11- coffee maker and a 15- frying pan are connected in series across a 120-V source of voltage. A 24- bread maker is also connected across the 120-V source and is in parallel with the series combination. Find the total current supplied by the source of voltage.

Answer 1

A 11- coffee maker and a 15- frying pan are connected in series across a 120-V source of voltage. A 24- bread maker is also connected across the 120-V source and is in parallel with the series combination. Find the total current supplied by the source of voltage.

Answer

$$\begin{array}{l} R_{1}(\text{resistance of coffee maker}) = 11 \text{ Ohm}, R_{2}(\text{resistance of frying pan}) \\ = 15 \text{ Ohm}, R_{3}(\text{resistance of bread maker}) = 24 \text{ Ohm} \end{array}$$

For serial connection:

$$R_{12} = R_{1} + R_{2} = 26 \text{ Ohm}$$

For parallel connection:

$$R = \frac{R_{12} R_{3}}{R_{12} + R_{3}} = 12,48 \text{ Ohm}$$

The total current supplied by the source of voltage

$$I = \frac{U}{R} = \frac{120 \text{ V}}{12,48 \text{ Ohm}} = 9,61538 \text{ A}$$