emf and internal resistance

Question 1

what is the emf defined as?

Answer 1

• the amount of chemical energy converted to electrical energy per coulomb of charge when passing through a power supply

Question 2

how can emf be directly measured?

Answer 2

• potential difference across the cell when no current flowing

Question 3

what is terminal potential difference

Answer 3

• the potential difference actoss the terminals of a cell
• if there was no internal resistance the terminal pd would be equal to the emf

Question 4

what is lost volts?

Answer 4

• the work done per unit charge to overcome the internal resistance inside the battery when current flows

Question 5

what is equation for emf?

Answer 5

emf = I ( R + r )

R = total resistance of load
r = internal resistance
I = current in circuit

emf = volts