What is the definition of "combination circuit"?
A route for the flow of electricity that has elements of both series and parallel circuits.

## Electrical Systems Training

Class Information
 Tooling U-SME classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
 Class Name: Parallel Circuit Calculations 205 Description: This class introduces the rules and formulas for parallel circuit calculations. Prerequisites: 550110  550115  550120 Difficulty: Intermediate Number of Lessons: 16 Language: English, Spanish

Class Outline
• Objectives
• Predicting Electrical Capacity
• Circuits
• Rules for DC Parallel Circuits
• Current in Parallel Circuits
• Voltage in Parallel Circuits
• Resistance in Parallel Circuits
• Determining Resistance: Resistors of Equal Value
• Determining Resistance: Product Over Sum
• Determining Resistance: Reciprocal Formula
• DC Parallel Circuit: Sample Problem
• Sample Problem: Calculating Voltage
• Sample Problem: Calculating Amperage
• Sample Problem: Calculating Power
• Combination Circuits
• Summary

Class Objectives
• Describe the importance of predicting electrical capacity.
• Distinguish between the functions of series and parallel circuits.
• List the rules for DC parallel circuits.
• Describe current flow in parallel circuits.
• Describe voltage in parallel circuits.
• Describe resistance in parallel circuits.
• Use the resistors of equal value method to determine resistance in a parallel circuit.
• Use the product over sum method to determine resistance in a parallel circuit.
• Use the reciprocal formula to determine resistance in a parallel circuit.
• Calculate the resistance in a sample DC parallel circuit.
• Calculate the voltage in a sample DC parallel circuit.
• Calculate amperage in a sample DC parallel circuit.
• Describe combination circuits.

Class Vocabulary

Vocabulary TermDefinition
A portion of a circuit that contains a load, and as a result, values for current, voltage, and resistance. The values of each branch of a circuit determine the total applied values for current, voltage, and resistance.
The amount of electricity that can safely flow through a wire without the wire overheating.
A route for the flow of electricity that has elements of both series and parallel circuits.
A part or component in a circuit that controls the flow of electricity.
The flow of electricity. Current is measured in amps.
A Kirchoff Law for DC parallel circuits stating that the total current of the circuit In a parallel circuit is the sum of the currents through each individual branch, regardless of the number of branches.
The expression in the bottom location of a fraction, below the fraction bar.
Current that travels in one direction. Direct current does not reverse the direction of flow.
A relationship where a number either increases as another decreases or decreases as another increases. Inversely proportional is the opposite of directly proportional.
A set of universal truths established by scientist Gustav Kirchoff that govern circuit calculations.
The part or component in a circuit that converts electricity into light, heat, or mechanical motion. Examples of loads are a light bulb, resistor, or motor.
The universal truth stating that it takes one volt to push one amp through one ohm.
A route for the flow of electricity that has a branched path for each load. Parallel circuits do not require all loads to be switched on in order for the other loads in the circuit to function.
A conductor that directs electricity in a circuit. The path is often copper wire.
The rate at which a device converts electrical energy into another form, such as heat or light. Power is measured in watts.
An equation for determining the total resistance for a parallel circuit. The product over sum method divides a pair of resistors, and then divides the result by another resistor, over and over again until only one pair is left.
An equation for determining the total resistance for a parallel circuit. The reciprocal formula finds the total resistance of a parallel circuit by calculating the reciprocal of the sum of the reciprocals of the individual branches.
The opposition to current flow. Resistance is measured in ohms.
A device that restricts current flow and produces work, such as heat.
An equation for determining the total resistance for a DC parallel circuit with resistors that have the same value. The resistors of equal value method finds the total resistance by dividing the value of one individual resistor by the number of branches.
A route for the flow of electricity that has only one path. Series circuits are limited because, for any load to work, every load in the circuit must be switched on.
The device that provides electrical power to a circuit. The source is the origin of electricity, such as a power plant.
Electrical pressure that causes current flow. Voltage is measured in volts.
The amount of voltage needed to push a given amount of current through a given amount of resistance.