Constructing and Interpreting
Electric Circuit Schematic Diagrams

The following questions are designed to enhance your understanding of the architecture, characteristics, and behavior of electrical circuits and the individual components of which they are comprised. It is recommended that you have your Reference Tables alongside and opened to the Electricity page while completing this exercise. It is also recommended that schematic diagrams be done initially in pencil. Remember to fully label all diagrams and to employ proper problem-solving techniques when performing calculations. All work must be shown.

A given circuit is comprised of three groups of resistors. The resistors in each group are connected in parallel. Each of the three groups are in turn connected in series to a 36V source of potential difference. The first group consists of three resistors, R1, R2, and R3, which possess resistance of 10 ohms, 15 ohms, and 20 ohms, respectively. The second group consists of two resistors, R4 and R5, which possess resistances of 6 ohms and 9 ohms, respectively. The third group consists of two resistors, R6 and R7, which possess resistances of 4 ohms and 12 ohms, respectively.

1. Sketch a schematic of the circuit based on the information provided above, using the standard circuit symbols outlined in the Reference Tables, and labeling each resistor.

2. Sketch an ammeter in a location where the total (equivalent) current of the circuit may be measured.

3. Calculate the total (equivalent) current available to the circuit.

4. Calculate the current passing through each resistor.

5. Sketch the devices and locations on your schematic diagram whereby the voltage drop across resistors R2, R4, and R7 may be measured.

6. Calculate the voltage drop across resistors R2, R4, and R7, and label the diagram accordingly.

7. Calculate the total power consumption of the circuit.

8. Calculate the total amount of energy that is consumed by the circuit in one hour.

Answer Key:

3. It = 3.2 amps

4.I1 = 1.5 amps
   I2 = 1.0 amps
   I3 = 0.7 amps
   I4 = 1.9 amps
   I5 = 1.3 amps
   I6 = 2.4 amps
   I7 = 0.8 amps

6.V2 = 14.8 volts
   V4 = 11.6 volts
   V7 = 9.6 volts

7. Pt = 115 watts

8. W = 4.2 x 10exp5 joules
Cycle III Physics
John Dewey High School
Mr. Klimetz