Heating Effect, Electrical Power and Maximum Power Transfer
Power dissipated is P = VI = I2 R = V2/R; a source of internal resistance r delivers maximum power when the load equals r.
What is Heating Effect, Electrical Power and Maximum Power Transfer?
Power dissipated is P = VI = I2 R = V2/R; a source of internal resistance r delivers maximum power when the load equals r.
Key formula / rule: P = VI = I2 R = V2/R; energy in kWh for billing.
Key points
- Compute power dissipation in circuit elements.
- Derive the maximum power transfer condition.
Common exam trap
Using V2/R for a series element whose voltage was not computed.
Definitions
- Term
Heating Effect, Electrical Power and Maximum Power Transfer
- Meaning
Power dissipated is P = VI = I2 R = V2/R; a source of internal resistance r delivers maximum power when the load equals r.
- Term
Heating Effect, Electrical Power and Maximum Power Transfer — explanation
- Meaning
Which power expression to use depends on what is held constant: I2R for series elements and V2/R for parallel ones.
Learning objectives
Compute power dissipation in circuit elements.
Derive the maximum power transfer condition.
Formulae
- Key point
P = VI = I2 R = V2/R; energy in kWh for billing.
- Key point
Terminal voltage V = E - Ir.
- Key point
Maximum power transfer at R = r, with 50 percent efficiency.
Prerequisites
PHY-U5-CUR-T1-S1-C2
PHY-U1-WEP-T2-S1-C1
Common mistakes
Using V2/R for a series element whose voltage was not computed.
Confusing maximum power transfer with maximum efficiency.
Keywords
Heating
Effect
Electrical
Power
Maximum
Power
Practice preview
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