DC Electricity - Test Review 3 (B.)

Rheostat

A variable resistor that has two terminals. - Used to adjust CURRENT in a circuit

Potentiometer

A variable resistor with a sliding contact that is used as a voltage divider with three terminals - Used to adjust VOLTAGE in a circuit - Derived from the word "Potential" or "voltage"

Open Circuit

An electric circuit in which the continuity is broken so that current does not flow.

Short Circuit

An electric circuit that contains no resistance to limit the flow of current.

Volt (E/V)

Voltage

Amp (I)

Current

Circuit Breakers

Devices designed to open under an abnormal amount of current flow. These devices are not damaged and may be used repeatedly. Rated by voltage, current, and horsepower.

Fuses

Devices used to protect a circuit or electric device from excessive current. These devices operate by melting a metal link when current becomes excessive.

Short circuit is possible

If a circuit is drawing way too much current, and lost its load (opposition to current flow) ____________.

Infinity

If the resistor is burned out, the ohmmeter will read ____________.

Short circuit

If the resistor reads high/infinity, this indicates a ____________.

Open circuit

When measuring a series circuit and the voltage is reads zero, it is an ____________.

Ohm (Omega)

Resistance

Watt (W)

Unit of Power

Continuity/ohmmeter

Use ____________ to check fuses/resistors.

IT = I1=I2=I3/ET = E1+E2+E3/RT = R1+R2+R3

Three (3) rules when using Ohm's Law for finding values of voltage, current, resistance and power in any series circuits (Formulas)

The current is the same at any point in the circuit/the total resistance is the sum of the individual resistors/the applied voltage is equal to the sum of the voltage drops across all the resistors

Three (3) rules when using Ohm's Law for finding values of voltage, current, resistance and power in any series circuits.

R = E/I

To find value of unknown (3rd) resistor, use the formula ____________.