Electrical Power

Electrical Power

Mr. Burnside

Wattage and Voltage

• There are four basic units of electricity that a computer technician must know

Multiple Choice

There are four basic units of electricity that a computer technician must know.

• True

• False

Voltage

• Voltage (V):The measure of work required to move a charge.

• Current (I) – Measured in Amperes(A) The measure of the amount of electrons moving through a circuit per second.

• Resistance (R) -– Measured in Ohms (O) – Refers to the opposition to the flow of current in a circuit

• Power (P) – Measured in Watts (W)-The measure of the work required to move electrons through a circuit multiplied by the # of electrons going through the circuit per second

Multiple Choice

How would you describe voltage?

• The measure of work required to move a charge

• The measure of the amount of electrons moving through a circuit per second.

• Refers to the opposition to the flow of current in a circuit

Multiple Select

How would you describe power?

• The measure of the work required to move electrons through a circuit multiplied by the # of electrons going through the circuit per second

• The measure of the amount of electrons moving through a circuit per second.

Multiple Choice

How resistance measured?

• Measured in Ohms (O)

• Measured in Watts (W)

• – Measured in Amperes(A)

Multiple Choice

How is Power measured?

• Measured in Amperes(A)

• Measured in Ohms (O)

• Measured in Watts (W)

Power Supply Voltage Settings

On the back of some power supplies is a small switch called the voltage selector switch

•This switch sets the input voltage to the power supply to either 110V / 115V or 220V / 230V.

•If a power supply does not have this switch, it automatically detects and sets the correct voltage.

Power Fluctuation Types

• Blackout - Complete loss of AC power. 

• Brownout - Reduced voltage level of AC power that lasts for a period of time

• Noise - Interference from generators and lightning

Power Fluctuation Types

• Spike - Sudden increase in voltage that lasts for a short period and exceeds 100 percent of the normal voltage on a line. 

• Power surge - Dramatic increase in voltage above the normal flow of electrical current

• 
  

Multiple Choice

Which condition refers to a reduced voltage level of AC power that lasts for an extended period of time?

• brownout

• sag

• spike

• surge

Multiple Choice

What electrical unit refers to the number of electrons moving through a circuit per second?

• current

• voltage

• resistance

• power

Multiple Choice

Interference from generators and lightning

• Noise

• Spike

• Power surge

• Brownout