10.4 Internal Resistance

Question 1

What is the internal resistance of a power supply

Answer 1

The resistance to the flow of current inside the power supply itself

Question 2

Define lost volts

Answer 2

Work done per unit charge converting electrical energy into heat energy inside a cell with internal resistance
Or…
The p.d across the internal resistor of a source emf

Question 3

Equation relating the emf of a power supply to its internal resistance, the current in a circuit and resistance

Answer 3

Emf = ( I x R ) + ( I x r )

Question 4

How is the emf and internal resistance of a power supply determined from a graph of terminal p.d against current

Answer 4

Calculate the gradient
Terminal p.d, emf = y - intercept

Question 5

State the formula relating energy transferred in time by an electrical component to the current flowing through the p.d across it

Answer 5

W = I x v x t

Question 6

Formula for the Ek gained by a charge particle when it is accelerated through a p.d

Answer 6

eV = 1/2 x m x v^2