# NCATT Study Guide: Basic Circuits & Calculations (AC & DC)

Explain the basic circuits with reference to the following term: Power
Product of applied voltage and current power in a DC circuit. Product of applied voltage and the current in phase with the voltage in an AC circuit.

Explain the basic circuits with reference to the following term: Joules
International measure of energy expended in the kilogram, meter, and second system of units. Also known as a Newton meter, a Joules is the amount of work done when a force of one newton moves an object one meter along the direction of the force.

Explain the basic circuits with reference to the following term: Series Circuits
Contains only one path for current, making current common through all components. Series circuit components are connected end to end.

Explain the basic circuits with reference to the following term: Parallel Circuits
Contains more than one path for current. Circuit components are connected directly across each other. Current is divided between each branch in the circuit.

Explain the basic circuits with reference to the following term: Complex Circuits
Contains a combustion of series and parallel circuits.

Explain the basic circuits with reference to the following term: Voltage Drop
Reduction in voltage caused by current flowing through a resistor.

Explain the basic circuits with reference to the following term: Resistors in Series Circuits
Causes a reduction of current in one circuit.

Explain the basic circuits with reference to the following term: Resistors in Parallel Circuits
Causes a reduction of current in multiple circuits.

Explain the basic circuits with reference to the following term: Kirchhoff’s Current Law (KCL)
States that “the algebraic sum of the current flowing away from any point in an electrical circuit is equal to the sum of the current flowing to that point.”

Explain the basic circuits with reference to the following term: Kirchhoff’s Voltage Law (KVL)
States that “the algebraic sum of all of the voltage drops in an closed circuit is equal to zero.”

Explain the basic circuits with reference to the following term: Kirchhoff’s Resistance Law (KRL)
States that “the total resistance in a series circuit is the sum of the individual resistances or loads in the circuit.”

Explain the basic circuits with reference to the following term: Bridge Circuits
Contains four impedances that form a square. Two diagonally opposite corners are connected to an input device. The other two diagonally opposite corners are connected to an output device.

What are the most common problems encountered while troubleshooting circuits?
Open resistors or contacts and shorts between conductors

Explain how to test the following circuit for defects using a multimeter: Series Circuits

Explain how to test the following circuit for defects using a multimeter: Parallel Circuits

Explain how to test the following circuit for defects using a multimeter: Complex Circuits with a Voltage Drop

Explain how to test the following circuit for defects using a multimeter: Resistors in Series Circuits

Explain how to test the following circuit for defects using a multimeter: Resistors in Parallel Circuits

Explain how to test the following circuit for defects using a multimeter: Bridge Circuits

Explain how mathematics is an integral part of electronics by using formula’s based on Ohm’s laws and Kirchhoff’s laws to show the relationship between the following term: Volts (V)

Explain how mathematics is an integral part of electronics by using formula’s based on Ohm’s laws and Kirchhoff’s laws to show the relationship between the following term: Ampere (A, amps)

Explain how mathematics is an integral part of electronics by using formula’s based on Ohm’s laws and Kirchhoff’s laws to show the relationship between the following term: Ohm

Explain how mathematics is an integral part of electronics by using formula’s based on Ohm’s laws and Kirchhoff’s laws to show the relationship between the following term: Watts (W)

Explain the formulas used in AC circuit calculations with reference to the following term: Period
Amount of time for one complete cycle of oscillation to take place.

Explain the formulas used in AC circuit calculations with reference to the following term: Peak Voltage
Voltage measured from zero voltage to the maximum number of volts generated

Explain the formulas used in AC circuit calculations with reference to the following term: Effective Value
Value of sine wave alternating current needed to produce the same amount of heat as the value of the direct current.

Explain the formulas used in AC circuit calculations with reference to the following term: Inductance
Electrical characteristic of a conductor. Inductance causes voltage to be produced when it is cut or crossed by lines of magnetic flux. Inductance causes the current to lag the applied voltage.

Explain the formulas used in AC circuit calculations with reference to the following term: Resonance
Electrical characteristics of a conductor. Resonance occurs in an electrical circuit when the inductive and capacitive reactances are equal.

Explain the formulas used in AC circuit calculations with reference to the following term: Capacitance
Electrical characteristics of a conductor. Capacitance is the amount of electrical charge that can be stored in a capacitor under a given amount of electrical pressure (voltage). Capacitance causes the current to lead the applied voltage.

Explain the formulas used in AC circuit calculations with reference to the following term: Reactance
Electrical characteristic of a conductor. Reactance is opposition to AC flow by coils and capacitors. Values are given in ohms.

Explain the advantages and disadvantages of DC/AC measurements. Emphasize the problems associated with improper used and storage of meters, as well as safety issues.

Explain and demonstrate how to use the following meter with an emphasis on which meters work best for various measurements and tests: Mutlimeter
Multi-function meter used to test current values, voltage values, or ohmic values (resistance). With the flip of a switch, a multimeter can be set up as an ammeter, voltmeter, or ohmmeter. Displays on a multimeter are provided in both analog and digital format. Use a multimeter whenever possible.

Explain and demonstrate how to use the following meter with an emphasis on which meters work best for various measurements and tests: Ammeter
Electrical testing instrument used to measure the amount of current flowing through a load. Values are given in amps. Some ammeters measure milliamps and microamps.

Explain and demonstrate how to use the following meter with an emphasis on which meters work best for various measurements and tests: Voltmeter
Electrical testing instrument used to measure electrical voltage across components. Values are given in volts. Use a voltmeter for measurements and calculations to find a probable effect.

Explain and demonstrate how to use the following meter with an emphasis on which meters work best for various measurements and tests: Ohmmeter
Electrical testing instrument used to measure resistance in a circuit or component. Values are given in ohms An ohmmeter provides an effective and quick way to test the condition of a switch.

Explain and demonstrate how to use the following meter with an emphasis on which meters work best for various measurements and tests: Oscilloscope
Electronic test instrument that displays the waveforms of electrical signals. Oscilloscopes measure voltages (AC peak to peak values), measure time to determine frequencies, and display phase relationships (comparisons of waveforms in time) to identify equipment malfunctions.