WorksheetsThévenin and Norton Theorems Quiz
Total questions: 10
Worksheet time: 5mins
Thévenin's Theorem states that any linear electrical network with voltage/current sources and resistances can be replaced at a pair of terminals by:
A single resistor in parallel with a current source
A single voltage source in series with a resistor
Two voltage sources in parallel
A single capacitor
To find the Thévenin voltage (VTh), you should:
Short the load terminals and measure current
Remove the load and calculate the open-circuit voltage across the terminals
Place a short across the terminals and measure voltage
Replace all sources with their internal resistances
The Norton current (IN) is equal to:
The open-circuit voltage divided by RTh
The current through the load when the terminals are short-circuited
The current through the load under normal operation
Zero if no independent sources exist
The Thévenin resistance (RTh) is found by:
Deactivating all independent sources and finding equivalent resistance between terminals
Measuring voltage across the load
Shorting the terminals and measuring current
Keeping sources active and calculating total resistance
When deactivating sources to find RTh or RN, ideal voltage sources are replaced with:
Open circuits
Short circuits
Their internal resistance
Capacitors
Norton’s Theorem is the dual of Thévenin’s Theorem and represents the network as:
A voltage source in series with a resistor
A current source in parallel with a resistor
Two current sources in series
A resistor only
If a circuit has no independent sources, then:
VTh = 0 V and IN = 0 A
RTh = 0 Ω
Both VTh and RTh are infinite
IN is maximum
For a given network, the relationship between Thévenin and Norton equivalents is:
VTh = IN × RTh
IN = VTh / RN
RTh ≠ RN
VTh = IN + RTh
Which of the following is true when applying Thévenin’s Theorem to a circuit containing dependent sources?
Dependent sources are deactivated
RTh is found by applying a test voltage or current at the terminals
VTh cannot be calculated
The theorem does not apply
A load resistor RL draws maximum power from a Thévenin equivalent circuit when:
RL = 0 Ω
RL = RTh
RL is much larger than RTh
RL is much smaller than RTh
