IB SL Physics 2025-32 - Current and circuits (B5)

Current and circuits (B5)

How do charge particles flow through materials?

How are the electrical properties of materials quantified?

What are the consequences of resistance in conductors?

that cells provide a source of emf
chemical cells and solar cells as the energy source in circuits
that circuit diagrams represent the arrangement of components in a circuit
direct current (dc) I as a flow of charge carriers (I=ΔQ/ΔT)
that the electric potential difference V is the work done per unit charge on moving a positive charge between two points along the path of the current as given by V = W/q
the properties of electrical conductors and insulators in terms of mobility of charge carriers
electric resistance and its origin
electrical resistance R (R=V/I)
resistivity (ρ =RA/L)
Ohm’s law
the ohmic and non-ohmic behaviour of electrical conductors, including the heating effect of resistors
electrical power P dissipated by a resistor as given by P = IV
the combinations of resistors in series and parallel circuits
that electric cells are characterized by their emf ε and internal resistance r as given by ε = I(R + r)
that resistors can have variable resistance.

Advantages and disadvantages of difference sources of electrical energy are required.
Refer to the Physics data booklet for the electrical circuit symbols that are required.
Alternating current (ac) circuits are not required.
Unless otherwise stated, ammeters and voltmeters will be considered as ideal.
In cases where non-ideal meters are used, the resistance will be constant.
A metal conductor at a constant temperature will be considered an ohmic device.
Variable resistors will be limited to thermistors, light-dependent resistors (LDR) and potentiometers.