Electricity 3 Flashcards
How do electrical cells produce a voltage
Chemical reaction
What does the emf of a cell stand for
Electromotive force
What is the definition of EMF
The energy given to each coulomb of charge passing through the source
What does an EMF of 12v mean
12j of energy given to each coulomb of charge passing through the source
What will a short circuit do to the battery
It will drain it quickly
What would happen if the circuit had 0 resistance
The current would be dangerously high
What can the EMF be measured as
The voltage across the source when no current is flowing
What is the TPD (Terminal Potential Difference)
The voltage measured across the terminals when current is flowing
What happens when the current flows
Energy is lost to the internal resistance and the voltage drops
What is the lost volts
The drop in voltage
What happens as the current increases
More volts are lost and the TPD decreases
What is the equation for total resistance
Rt = R = r
What is the equation for TPD
TPD = IR
What is the equation for lost volts
Lv = Ir
What is the equation for the EMF
EMF = TPD + Lv
