Date post: | 04-Jan-2016 |
Category: |
Documents |
Upload: | eunice-perkins |
View: | 218 times |
Download: | 2 times |
Electrical Systems
VOCABULARY OBJECTIVES Series circuit Voltage drop Kirchoff’s Voltage
Law
• Describe a series circuit.
• Calculate the resistance and current in a series circuit.
• Explain how the voltage changes across each resistor in a series circuit.
• A series circuit has one path A series circuit contains only one path for
electric current to flow. The current is the same at all points in the
circuit.
• Stopping the current If there is a break at any point in the circuit,
the current will stop. Ex. Holiday Lights
• Using series circuits Devices are connected in series for specific
purposes. Ex. switches
Use Ohm’s Law You can use Ohm’s law to calculate the
current in a circuit if you know the voltage and resistance.
Adding Resistances Rtotal = R1 + R2 + R3 + …
Ignoring resistances Everything has some resistance, even
wires. However, sometimes the resistance of
an object is so small that we can ignore it when compared to other objects.
Energy changes forms Energy cannot be created nor destroyed Devices in a circuit convert electrical
energy Voltage decreases after each device that
uses power, known as voltage drop. Voltage drop is the difference in voltage
across an electrical device. Charges lose their energy
The current in a series circuit is the same everywhere.
As power gets used, the voltage gets lower.
Voltage If three bulbs are identical each gives off
the same amount of light and heat. Each uses the same amount of power.
• Voltage drops– Each separate bulb or resistor creates a
voltage drop.– Voltage drop across a bulb is measured
by an electric meter.– The greater the voltage drop, the
greater the amount of power being used per amp of current flowing through the bulb.
• Ohm’s Law– Voltage drop across a distance is
measure by Ohm’s Law.
Energy conservation The Law of Conservation of Energy also
applies to a circuit. Over an entire circuit, the power used by
all the bulbs must equal the power supplied by the battery.
The total of all the voltage drops must add up to the battery’s voltage, known as Kirchoff’s voltage law.