Download In a series circuit

Module 2: Series Circuits
Module Objectives:
Upon completion of this module, students should be able to:
1. Explore the idea of a series circuit.
2. Understand how to draw a circuit diagram of a series circuit.
3. State the voltage, current, resistance, and power characteristics of a
series circuit.
4. Solve for unknown circuit values in a series circuit.
5. Use a multimeter to measure the potential differences (voltages),
currents and resistance of series circuits.
6. Apply the concepts of relative polarity, series adding, and series
opposing voltages.
7. Study the applications of voltage divider calculations
8. Apply Ohm’s Law to calculate resistance, voltage and current in
series circuits.
9. Verify Kirchhoff’s Voltage Law in a series circuit.
10.Recognize some basic applications of series circuits.
Series Circuits
2.1 Introduction to series
circuits
A series circuit is a circuit that has
only one path for current flow.
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Circuit Diagram
Circuit diagram shows the physical details
of the circuit.
Schematic diagram uses symbols to
represent each circuit component.
Schematic diagram
Notes: In a series circuit:
• If a lamp 'blows' or a component is
disconnected, all the components
stop working.
• If you put more lamps into a series
circuit, the lamps will be dimmer.
2.2 Identifying Circuit Components
Current is the same in the series circuit
In a series circuit, the total voltage equals the
sum of the voltage across the batteries wired
in series in the circuit.
In a series circuit, the total resistance (in ohms) equals
the sum of the resistance of each device using
electricity.
2.4 Series Circuit Formulas
IT = I1 = I2 = I3
VT = V1 + V2 + V3
RT = R1 + R2 + R3
Power in series circuits
The total power dissipated (Pt) in a series
circuit is always the sum of the power
dissipated by the individual resistors or
the product of the total current (It) and
the source voltage (Vt).
PT = IT x VT
Summary Table
Ohm's Law can be used to solve for any
of the individual values or for the total
value of each measure within the series
circuit.
Two lamps are
dimmer
Single lamp
is brighter
2.5 Voltage Sources in Series
When the polarities of the power sources
are connected in the same direction as
shown here, they are referred to as Series
aiding
When the polarities of power sources are
connected in opposite directions as shown,
their voltages cancel, and are referred to as
Series opposing
Solve example 1.1 - page 10
2.6 Voltage Divider Rule
The two resistor voltage divider as shown here
is used often to supply a voltage different from
that of an available battery or power supply.
The voltage drop across any given
resistor in a series circuit is equal to
Solve example 2.2- page 11
2.7 Kirchhoff's Voltage Law
Kirchhoff’s voltage law (KVL) is generally
stated as:
The sum of all the voltage drops around a
single closed path in a circuit is equal to
the total source voltage in that closed path.
Solve exercises - page 17,18