(IB)

The material that follow are __ reproduced with the permission of the International
Baccalaureate Organization__.

**For my physics notes, questions and solutions to '25' physics topics, click here**.

I would like to specially thank Pat Adams, the Publications Manager of the International
Baccalaureate Organisation for allowing me to use the extract about the 'Nature
of the Subject' and sections of the "Syllabus Details" reproduced below from the IB Diploma Programme guides: *Physics*, February 2001 and *April 1996*
Guide.

** Standard level** students will study six topics: Physics and Physical Measurement, Mechanics, Thermal Physics, Waves, Electricity and Magnetism and Atomic and Nuclear Physics.

** Higher level** students, in addition to the above six topics, will study six more topics: Measurements and Uncertainties, Mechanics, Thermal Physics, Wave Phenomena, Electromagnetism and Quantum Physics and Nuclear Physics.

** Standard level** students will study any

** Higher level** students will study any

While every effort has been made to type this material carefully, I shall be pleased to rectify any errors that have inadvertantly crept in. Please remember that the

Physics is the most fundamental of the experimental sciences as it seeks to explain the universe itself, from the very smallest particles - quarks (perhaps 10^{-17} m in size) which may be truly fundamental to the vast distances between galaxies ( 10^{24} m).

Classical physics, built upon the great pillars of Newtonian mechanics, electromagnetism and thermodynamics, went a long way in deepening our understanding of the universe. From Newtonian mechanics came the idea of predictability in which the universe is deterministic and knowable. This led to Laplace's boast that by knowing the initial conditions - the position and velocity of every particle in the universe - he could, in principle, predict the future with absolute certainty. Maxwell's theory of electromagnetism described the behaviour of electric charge and unified light and electricity, while thermodynamics described the relation between heat and work and described how all natural processes increase disorder in the universe.

However, experimental discoveries dating from the end of the nineteenth century eventually led to the demise of the classical picture of the universe as being knowable and predictable. Newtonian mechanics failed when applied to the atom and has been superseded by quantum mechanics and general relativity. Maxwell's theory could not explain the interaction of radiation with matter and was replaced by quantum electrodynamics (QED). More recently, developments in chaos theory, in which it is now realized that small changes in the initial conditions of a system can lead to completely unpredictable outcomes, have led to a fundamental rethinking in thermodynamics.

While chaos theory shows that Laplace's boast is hollow, quantum mechanics and QED show that the initial conditions Laplace required are impossible to establish. Nothing is certain and everything is decided by probability. But there is still much that is unknown and there will undoubtedly be further paradigm shifts as our understanding deepens.

Despite the exciting and extraordinary development of ideas throughout the history of physics, certain things have remained unchanged. Observations remain essential at the very core of physics, and this sometimes requires a leap of imagination to decide what to look for. Models are developed to try to understand the observations and these themselves can become theories which attempt to explain the observations. Theories are not directly derived from the observations but need to be created. These acts of creation can sometimes compare to those in great art, literature and music, but differ in one aspect which is unique to science: the predictions of these theories or ideas must be tested by careful experimentation. Without these tests a theory is useless. A general or concise statement about how nature behaves, if found to be experimentally valid over a wide range of observed phenomena, is called a law or a principle.

The scientific processes carried out by the most eminent scientists in the past are the same ones followed by working physicists today and, crucially, are also accessible to students in schools. Early in the development of science physicists were both theoreticians and experimenters (natural philosophers). The body of scientific knowledge has grown in size and complexity and the tools and skills of theoretical and experimental physicists have become so specialized that it is difficult (if not impossible) to be highly proficient in both areas. While students should be aware of this, they should also know that the free and rapid interplay of theoretical ideas and experimental results in the public scientific literature maintains the crucial links between these fields.

At the school level both theory and experiments should be undertaken by all students. They should complement one another naturally, as they do in the wider scientific community. The Diploma Programme physics course allows students to develop traditional practical skills and techniques and increase facility in the use of mathematics, which is the language of physics. It also allows students to develop interpersonal skills, and information and communication technology skills which are essential in modern scientific endeavour and are important life-enhancing, transferable skills in their own right.

Alongside the growth in our understanding of the natural world, perhaps the more obvious and relevant result of physics to most of our students is our ability to change the world. This is the technological side of physics in which physical principles have been applied to construct and alter the material world to suit our needs, and have had a profound influence on the daily lives of all human beings; for good or bad. This raises the issue of the impact of physics on society, the moral and ethical dilemmas and the social, economic and environmental implications of the work of physicists. These concerns have become more prominent as our power over the environment has grown, particularly amongst young people for whom the importance of the responsibility of physicists for their own actions is self-evident.

Physics is therefore, above all, a human activity and students need to be aware of the context in which physicists work. Illuminating its historical development places the knowledge and the process of physics in a context of dynamic change in contrast to the static context in which physics has sometimes been presented. This can give students insights into the human side of physics: the individuals; their personalities, times and social milieux; and their challenges, disappointments and triumphs.

__Topic 1__: **Physics and Physical Measurement**

**1.1 The Realm of Physics**

*Range of magnitudes of quantities in our universe*

**1.1.1** State (express) quantities to the nearest order of magnitude.

**1.1.2** State the ranges of
magnitude of sizes, masses and times that occur in the universe, from smallest
to greatest.

Sizes-from 1O^{-15} m to 10^{25} m (subnuclear particles to extent of the visible universe).

Masses-from 10^{-30} kg to 10^{50} kg (electron to mass of the universe).

Times from 10^{-23} s to l0^{18} s (passage of light across a nucleus to the age of the universe).

**1.1.3** State and compare the order of magnitude of selected (significant) systems in the universe.

Students should become familiar with the order of magnitudes of significant systems with which they deal, and aim to develop a familiarity with the orders of magnitudes of important masses, lengths. times and other quantities.

**1.1.4** State (express) ratios of quantities as differences of orders of magnitude.

For example, the ratio of the diameter of the hydrogen atom to its nucleus is about lO^{5} times, or a
difference of five orders of magnitude.

**1.2 Measurement and Uncertainties **

*The SI system of fundamental and derived units*

**1.2.1** State the fundamental units in the SI system.

Students need to know the following: kilogram, meter, second, ampere, mole and kelvin.

**1.2.2** Distinguish between, and give examples of, fundamental and derived units.

**1.2.3** Convert between different units for quantities.

For example, J and kWh, J and eV, years and seconds, and between other systems and SI.

**1.2.4** State units in the accepted SI format.

Use ms^{-2} not m/s/s and ms^{-1} not m/s.

**1.2.5** State values in scientific notation and in multiples of units with appropriate prefixes.

For example, use nanoseconds or gigajoules.

*Uncertainty and error in experimental measurement*

**1.2.6** Describe, distinguish between and give examples of random uncertainties and systematic errors.

**1.2.7** Distinguish between *precision* and *accuracy*.

For example, repeated measurements on a voltmeter may have great precision in that they are highly reproducible with small scatter and uncertainty, yet they may be inaccurate (for example if the voltmeter has a zero offset error).

**1.2.8** Explain how the effects of random uncertainties may be reduced.

Students should be aware that systematic errors are not reduced by repeating readings.

**1.2.9** State random uncertainty as an uncertainty range (±) and represent it graphically as an "error bar".

**1.2.10** Identify values of quantities and results of calculations to the appropriate number of significant digits.

The number of significant digits should reflect the precision of the value or of the input data to a calculation. Only a simple rule is required: for multiplication and division, the number of significant digits in a result should not exceed that of the least precise value upon which it depends.

**1.3 Mathematical and Graphical Techniques **

*Estimation*

**1.3.1** Estimate approximate values of everyday quantities to one or two significant digits and/or to the nearest order of magnitude.

Reasonable estimates for common quantities, eg dimensions of a brick, mass of an apple, duration of a heartbeat or room temperature are expected.

**1.3.2** State and explain simplifying assumptions in approaching and solving problems.

For example, reasonable assumptions that certain quantities may be neglected, others ignored (eg heat losses, internal resistance), or that behaviour is approximately linear.

**1.3.3** Estimate results of calculations.

Examples:

174/118 = 180/120 = 3/2 = 1.5

or 6.3 x 7.6/4.9 ~ 6 x 8/5 = 48/5 = 50/5 = 10.

*Graphs*

**1.3.4** Construct graphs from data, choosing suitable scales for the axes.

Include or suppress the zero on an axis as appropriate.

**1.3.5** Draw qualitative graphs to represent dependencies and interpret graph behaviour.

Students should be able to give a qualitative physical interpretation of a particular graph, eg as the potential difference increases, the ionization current reaches a maximum.

**1.3.6** Determine the values of physical quantities from graphs.

Include measuring and interpreting the slope (gradient), intercepts and area under a curve, and stating the units for these quantities.

**1.3.7** Draw best-fit lines to data points on a graph.

These can be curves or straight lines as appropriate. Fitting by eye is expected. Mathematical fitting is not required. Students should not join data points with segments.

*Graphical analysis and determination of relationships*

**1.3.8** Transform equations into generic straight-line form y = mx + c and plot the corresponding graph.

This can include plotting various functions of the variables such as reciprocals, powers and roots. Logarithmic functions are not required.

**1.3.9** Analyse a straight-line graph to determine the equation relating the variables.

The parameters of the original function can be obtained from the slope m and intercept c.

**1.4 Vectors and Scalars **

**1.4.1** Distinguish between vector and scalar quantities, and give examples of each.

When expressing a vector as a symbol, students should adopt a recognised notation.

1**.4.2** Draw arrows of appropriate length and direction to represent vector quantities.

**1.4.3** State vector quantities either in terms of magnitude and direction or by their components along chosen axes.

**1.4.4** Add and subtract vector quantities by the graphical method.

Add and subtract accurately by construction, or approximately, if an estimate is required. Multiplication and division of vectors by scalars is also required.

**1.4.5** Resolve vectors into perpendicular components along chosen axes.

For example, resolving parallel and perpendicular to an inclined plane. Choose appropriate axes along which to resolve according to the needs of the physical situation.

**1.4.6** Interpret the physical meaning of vector components where appropriate.

For example, interpret vertical and horizontal components of velocity in projectile motion, or force components along and perpendicular to an inclined plane.

**1.4.7** Add two or more vectors by the method of components.

First resolve into components, then add the components and recombine them into a resultant vector. Pythagoras' theorem and basic trigonometry are required but not the sine and cosine rules.

**1.4.8** Solve problems involving the vector nature of physical quantities.

Problems may involve the vector nature of quantities such as displacement, velocity, acceleration, momentum, force and fields.

__Topic 2__: **Mechanics**

**2.1 Kinematics**

*Kinematic concepts*

**2.1.1** Define *displacement*, *velocity*, *speed* and *acceleration*.

Quantities should be identified as scalar or vector quantities.

**2.1.2** Define and explain the difference between *instantaneous* and *average* values of speed. velocity and acceleration.

**2.1.3** Describe an oh motion from more than one frame of reference.

Students should be familiar with the term *relative velocity* and should be able to calculate relative velocities in one dimension.

*Graphical representation of motion*

**2.1.4** Draw and analyse distance-time graphs, displacement-time graphs, velocity-time graphs and acceleration-time graphs.

Students should be able to sketch and label these graphs for various situations. They should also be able to write descriptions of the motions represented by such graphs.

**2.1.5 **Analyse and calculate the slopes of displacement-time graphs and velocity-time graphs, and the areas under velocity-time graphs and acceleration-time graphs. Relate these to the relevant kinematic quantity.

*Uniformly accelerated motion*

**2.1.6** Determine the velocity and acceleration from simple timing situations.

Students should be able to interpret data from devices such as a light gate, strobe photograph or ticker timer. Analysis may involve graphing the data, taking measurements and applying kinematics concepts.

**2.1.7** Derive the equations for uniformly accelerated motion.

**2.1.8** Describe the vertical motion of an object in a uniform gravitational field.

**2.1.9** Describe the effects of air resistance on falling objects.

Only qualitative descriptions are expected. Students should understand the term terminal velocity.

**2.1.10** Solve problems involving uniformly accelerated motion.

**2.2 Forces and Dynamics **

*Forces and free-body diagrams*

**2.2.1** Describe force as the cause of deformation or velocity change.

**2.2.2** Identify the forces acting on an object and draw free-body diagrams representing the forces acting.

Each force should be labelled by name or given a commonly accepted symbol. Vectors should have lengths approximately proportional to their magnitudes.

**2.2.3** Resolve forces into components.

**2.2.4** Determine the resultant force in different situations.

**2.2.5** Describe the behaviour of a linear spring and solve related problems. Spring combinations will not be assessed.

*Newton's first law*

**2.2.6** State Newtons first law of motion.

**2.2.7** Describe examples of Newton's first law.

*Equilibrium*

**2.2.8** State the condition for translational equilibrium.

**2.2.9 **Solve problems involving translational equilibrium.

*Newton's second law*

**2.2.10** State Newton's second law of motion.

Students should be familiar with the law in both the forms F = ma and F = ðp/ðt

**2.2.11** Solve problems involving Newton's second law.

*Newton's third law*

**2.2.12** State Newton's third law of motion.

Students should understand that when two bodies A and B interact, the force that A exerts on B is equal and opposite to the force that B exerts on A.

**2.2.13** Discuss examples of Newton's third law.

**2.3 Inertial Mass, Gravitational Mass and Weight **

**2.3.1** Define *inertial mass*

Students should describe inertial mass as the ratio of resultant force to acceleration.

**2.3.2** Compare gravitational mass and inertial mass.

Students should understand that although the concepts of gravitational mass and inertial mass are different. they have identical values. A simple argument should be given to show that the equivalence of gravitational mass and inertial mass accounts for objects having the same value for free-fall acceleration.

**2.3.3** Discuss the concept of *weight*.

Students should understand that usage of the term weight can be ambiguous. weight can mean the gravitational force mg and the reading on a supporting scale: these have different values in non-equilibrium situations.

**2.3.4** Distinguish between mass and weight.

**2.4 Momentum **

**2.4 1** Define *linear momentum* and *impulse*.

**2.4.2** State the law of conservation of linear momentum.

**2.4.3** Derive the law of conservation of momentum for an isolated system consisting of two interacting particles.

The law is derived by applying Newton's second law to each particle and Newton's third law to the system.

**2.4.4** Solve problems involving momentum and impulse.

Students should be familiar with elastic and inelastic collisions and explosions.

**2.5 Work, Energy and Power **

*Work*

**2.5.1** Define *work*.

Students should be familiar with situations where the displacement is not in the same direction as the force.

**2.5.2** Determine the work done by a non-constant force by interpreting a force-displacement graph.

**2.5.3** Solve problems involving the work done on a body by a force.

*Energy and power*

**2.5.4** Define *kinetic energy*.

**2.5.5** Describe the concepts of gravitational potential energy and elastic potential energy.

**2.5.6** State the principle of conservation of energy.

**2.5 7** List different forms of energy and describe examples of the transformation of energy from one form into another.

**2.5.8** Define *power*.

**2.5.9** Define and apply the concept of efficiency.

**2.5.10** Solve work, energy and power problems.

**2.6 Uniform Circular Motion **

**2.6.1** Draw a vector diagram to show that the acceleration of a particle moving with uniform speed in a circle is directed toward the centre of the circle.

**2.6.2** State the expression for centripetal acceleration.

**2.6.3** Identify the force producing circular motion in various situations.

Examples include gravitational force (acting on the moon) and friction (acting sideways on the tyres of a car turning a corner).

**2.6.4** Solve problems for particles moving in circles with uniform speed.

__Topic 3__: **Thermal Physics**

**3.1 Thermal Concepts**

*Temperature and thermometers*

**3.1.1** State that temperature is a property that determines the direction of thermal energy transfer between two bodies in thermal contact.

Students should be familiar with the concept of thermal equilibrium.

**3.1.2** Explain how a temperature scale is constructed.

**3.1.3** State the relation between the Kelvin and Celsius scales of temperature. T/K = t/°C + 273 is sufficient.

*Heat and internal energy*

**3.1.4** State that temperature is a measure of the average kinetic energy of the molecules of a substance.

**3.1.5** State that internal energy is the total potential and kinetic energy of molecules in a substance.

Students should know that the kinetic energy of the molecules arises from their translational/rotational motion and that the potential energy of the molecules arises from the forces between the molecules.

**3.1.6** Explain and distinguish between the macroscopic concepts of temperature, internal energy and heat.

*Thermal energy transfer*

**3.1.7** Describe qualitatively, the processes of conduction, convection and radiation.

**3.1.8** Describe examples of conduction. convection and radiation.

**3.2 Thermal Properties of Matter **

*Specific heat capacity*

**3.2.1** Define and distinguish between heat capacity and specific heat capacity.

**3.2.2** Explain why different substances have different specific heat capacities.

This should be understood in terms of the fact that unit masses of different substances contain different numbers of molecules of different mass.

**3.2.3** Describe methods to measure the specific heat capacity of solids and liquids.

The electrical method and the method of mixtures are sufficient. The cooling correction is not included in the calculation. Sources of experimental error should be identified and ways to reduce these should be known. Constant flow techniques are not required.

**3.2.4** Solve problems involving specific heat capacities.

*Phases (states) of matter and latent heat*

**3.2.5** Describe the solid, liquid and gaseous states in terms of molecular structure and motion.

Only a simple model is required. The speed distribution in eases should be explained qualitatively. Students should he aware how microscopic structure explains bulk behaviour.

**3.2.6** Describe and explain the process of phase changes in terms of molecular behaviour.

**3.2.7** Explain in terms of molecular behaviour why temperature does not change during a phase change.

**3.2.8** Define *specific latent heat*.

**3.2.9** Describe a method for measuring the specific latent heat of fusion and a method for measuring the specific latent heat of vaporization.

Adding ice to water in a calorimeter would be suitable for fusion and an electrical method would be suitable for vaporization.

**3.2.10** Solve problems involving specific latent heats.

Problems may include all three phases of a substance and specific heat calculations.

**3.2.11** Describe the evaporation process in a liquid in terms of molecular behaviour.

Students should be aware that evaporation takes place at all temperatures and results in the cooling of a liquid.

**3.2.12** Identify factors that affect evaporation rate.

**3.3 Ideal Gases**

*Gas laws*

**3.3.1** State the macroscopic gas laws relating pressure. volume and temperature.

Students should be aware that real gases deviate from these laws under certain conditions and that an ideal gas is one that follows the gas laws for all values of p, V and T.

**3.3.2** Define the terms *mole* and *molar mass*.

Students should be able to convert between mass and number of moles.

**3.3.3** Define the *Avogadro constant*.

**3.3.4** State that the equation of state of au ideal gas is pV=nRT.

**3.3.5** Describe the concept of the absolute zero and the Kelvin scale.

**3.3.6** Solve problems using the equation of state of an ideal gas.

*Kinetic model of an ideal gas*

**3.3.7** Describe the kinetic model of an ideal gas.

Students should be able to describe how the pressure arises from the collisions of the molecules with the walls of the container.

**3.3.8** Explain the macroscopic behaviour of an ideal gas in terms of the molecular model.

Only qualitative explanations are required.

__Topic 4__: **Waves**

**4. 1 Travelling Waves**

*Waves*

**4.1.1** Describe a wave pulse and a continuous travelling wave.

Students should be able to distinguish between the oscillations and the wave motion.

**4.1.2** State that waves transfer energy.

Students should understand that there is no net motion of the medium through which the wave travels.

**4.1.3** Describe and give examples of transverse and longitudinal waves.

Students should know that sound is a longitudinal wave and that light is a transverse wave.

**4.1.4** Describe waves in two dimensions, including the concepts of wave fronts and rays.

*Wave characteristics*

**4.1.5** Define *displacement*, *amplitude*, *period*, *frequency*, *wavelength* and *wave speed*.

**4.1.6** Describe the terms *crest*, *trough*, *compression* and *rarefaction*.

**4.1.7** Draw and explain displacement-time and displacement-position graphs for transverse and longitudinal waves.

**4.1.8** Derive and apply the relationship between wave speed. wavelength and frequency.

**4.2 Wave Properties**

**Note**: Although the properties apply to all waves, students should be familiar with the particular cases of sound, light and water.

*Reflection, refraction and transmission of waves*

**4.2.1** Describe the reflection and transmission of one-dimensional waves at a boundary between two media.

This should include the sketching of incident, reflected and transmitted waves, and the cases of reflection at free and fixed ends.

**4.2.2** State Huygens' principle.

**4.2.3** Apply Huygens' principle to two-dimensional plane waves to show that the angle of incidence is equal to the angle of reflection.

**4.2.4** Explain refraction using Huygens principle.

**4.2.5** Derive, using Huygen's' principle, Snell's law for refraction.

The concept of refractive index is not required but the ratio of speeds is expected.

**4.2.6** State and apply Snell's law.

*Wave diffraction and interference*

**4.2.7** Explain and discuss qualitatively. using Huygens' principle, the diffraction of waves by apertures and obstacles.

The effect of wavelength compared to obstacle size or aperture size should be discussed.

**4.2.8** Describe examples of diffraction.

**4.2.9** State the principle of superposition and explain what is meant by constructive and destructive interference.

**4.2.10** Apply the principle of superposition to find the resultant of two waves.

Only one-dimensional situations need to be considered.

*Doppler effect*

**4.2.11** Describe the Doppler effect.

Only a simple description of the effect for both sound and light is required.

**4.3 Standing Waves **

*Nature and production of standing waves*

**4.3.1** Describe the nature of standing waves.

**4.3.2** Explain the formation of standing waves in one dimension.

**4.3.3** Compare standing waves and travelling waves.

*Boundary conditions and resonance*

**4.3.4** Explain the concept of resonance and state the conditions necessary for resonance to occur.

**4.3.5** Describe the fundamental and higher resonant modes in strings and open and closed pipes.

Note that fundamental and first harmonic are interchangeable terms.

**4.3.6** Solve problems involving the fundamental and higher harmonic modes for stretched strings and open and closed pipes.

End correction is not required.

__Topic 5__: **Electricity and Magnetism**

**5.1 Electrostatics **

*Electric charge*

**5.1.1** Describe the process of "electrification" by friction.

**5.1.2** State that there are two types of electric charge.

**5.1.3** State and apply the concept of conservation of charge.

**5.1.4** Describe and explain the properties of conductors and insulators.

Students should explain the properties in terms of the freedom of movement of electrons.

**5.1.5** Explain and describe the process of electrostatic induction.

**5.1.6** Describe the use of the gold leaf electroscope.

*Electric force and electric field*

**5.1.7** State Coulomb's law.

Students should be aware of the law in the forms

F = q_{1}q_{2}/4*Æ*_{0}r^{2}

and F = kq_{1}q_{2}/r^{2}

**5.1.8** Apply Coulomb's law.

The use of vector addition to determine the net force on a charge due to two or more other charges is expected.

**5.1.9** Define *electric field*.

Students should understand the meaning of test charge.

**5.1.10** Determine the electric field due to one or more point charges.

**5.1.11** Draw and explain electric field patterns for different charge configurations.

Students should be familiar with a point charge, a charged sphere, two point charges and oppositely charged parallel plates. The latter includes edge effect. Students should be aware of the term *radial field*.

*Electric potential energy and electric potential difference*

**5.1.12** Define the electric potential energy difference between two points in an electric field.

Calculations are to be confined to uniform electric fields.

**5.1.13** Determine the change in potential energy or change iii kinetic energy when a charge moves between two points at different potentials.

**5.1.14** Define the *electronvolt*.

Students should be able to relate the electronvolt to the joule.

**5.1.15** Define *electric potential difference*.

**5.1.16** Solve problems involving electric potential difference and electric potential energy.

**5.2 Electric Current and Electric Circuits **

*Electric current*

**5.2.1** Describe a simple model of electrical conduction in a metal.

Students should be aware of the term *drift velocity* and of the interactions of conduction electrons with the lattice ions.

**5.2.2** Define *electric current*.

Students should recognize the ampere as a fundamental unit.

**5.2.3** Define and apply the concept of resistance.

Students should be aware that R=V/I is a general definition of resistance. It is not a statement of Ohm's law. Students should be familiar with the term *resistor*.

**5.2.4** State Ohm's law.

**5.2.5** Compare ohmic and non-ohmic behaviour.

For example, students should be able to draw the I-V characteristics of a filament lamp.

**5.2.6** Derive and apply expressions for electrical power dissipation in resistors.

*Electric circuits*

**5.2.7** Define *electromotive force*.

**5.2.8** Describe the concept of internal resistance.

**5.2.9** Derive and apply the equations for equivalent resistances of resistors in series and in parallel.

**5.2.10** Draw circuit diagrams.

Students should be able to recognize and use the accepted circuit symbols included in the *Physics Data Booklet*.

**5.2.11** Describe the use of ammeters and voltmeters.

Students should be able to describe and draw the correct positioning of ideal ammeters and voltmeters in circuits. Students will not be required to know about shunts and multipliers.

**5.2.12** Solve problems involving series and parallel circuits.

Students should appreciate that many circuit problems can be solved by regarding the circuit as a potential divider. Students should be aware that ammeters and voltmeters have their own resistance.

**5.3 Magnetism**

*Magnets and magnetic fields*

**5.3.1** Draw the pattern of magnetic field lines of an isolated bar magnet.

**5.3.2** Draw the magnetic field pattern for the Earth.

Students should understand that the Earth's magnetic field is similar to that of a bar magnet with a south magnetic pole near the geographic north pole. and that an isolated suspended magnet will orientate itself along the Earth's magnetic field with its magnetic north pole directed towards the Earth's geographic north pole. They should recognize the compass as one example of a suspended bar magnet.

**5.3.3** Draw and annotate magnetic fields due to currents.

These include fields around a straight wire, a flat circular coil and a solenoid. Students should recognize that the magnetic field pattern of a solenoid is similar to that of a bar magnet.

*Magnetic forces*

**5.3.4** Determine the direction of the force on a current-carrying conductor in a magnetic field.

Different rules may be used to determine the force direction. Knowledge of any particular rule is not required.

**5.3.5** Determine the direction of the force on a charge moving in a magnetic field.

**5.3.6** Define the magnitude of the magnetic field strength *B*.

This can be defined in terms of the force acting either on a current-carrying conductor or on a moving charge.

**5.3.7** Solve problems involving the magnetic forces on currents and moving charges.

Students should be able to calculate the force for situations where the velocity is not perpendicular to the magnetic field direction.

**5.3.8** Draw the magnetic field pattern due to two parallel current-carrying wires.

**5.3.9** Solve problems involving the magnetic forces between two parallel current-carrying wires.

**5.3.10** State and explain the definition of the ampere.

Students should be able to explain how the force between two long parallel currents is the basis of the definition of the ampere.

**5.3.11** Explain the operation of a simple direct current (dc) motor.

Students should understand the components of dc motors, such as the commutator and the brushes.

*The magnetic field due to currents*

**5.3.12** Solve problems involving the magnetic field strength around a straight wire.

**5.3.13** Solve problems involving the magnetic field strength within a solenoid. Students should be aware that *B* depends on the nature of the solenoid core.

__Topic 6__: **Atomic and Nuclear Physics**

**6. 1 The Atom **

*Atomic structure*

**6.1.1** Describe a model of the atom that features a small nucleus surrounded by electrons.

**6.1.2** Outline the evidence that supports a nuclear model of the atom.

A qualitative explanation of the Geiger-Marsden experiment and its results is all that is required.

**6.1.3** Outline evidence for the existence of atomic energy levels.

Students should be familiar with emission and absorption spectra. but the details of atomic models are not required.

*Nuclear structure*

**6.1.4** Describe the existence of isotopes as evidence for neutrons.

**6.1.5** Explain the terms *nuclide*, *isotope* and *nucleon*.

**6.1.6** Define *mass number* and *atomic number*.

**6.1.7** Describe the interactions in the nucleus.

Students should be aware that there is a Coulomb interaction between protons and a strong, short-range nuclear interaction between the nucleons.

**6.2 Radioactive Decay**

*Radioactivity*

**6.2.1** Describe the phenomenon of natural radioactive decay.

**6.2.2** Describe alpha, beta and gamma radiation and their properties.

**6.2.3** Describe the ionizing properties of radiation and its use in the detection of radiation.

The Geiger-Muller tube and the ionization chamber are examples of such detection devices. Only a qualitative understanding of the operation of these devices is required.

**6.2.4** Explain why some nuclei are stable while others are unstable.

An explanation in terms of relative numbers of protons and neutrons and the forces involved is all that is required.

**6.2.5** Determine the atomic and mass numbers of the products of nuclear decay in a transformation or in a series of transformations

Positron decay and the inclusion of the antineutrino in beta minus decay are not required but teachers should not artificially avoid mentioning them.

*Half-life*

**6.2.6** State that radioactive decay is a random process and that the average rate of decay for a sample of a radioactive isotope decreases exponentially with time.

Exponential decay need not be treated analytically. It is sufficient to know that any quantity that reduces to half its initial value in a constant time decays exponentially and that this law does not depend on the initial amount of the quantity.

**6.2.7** Define the term *half-life*.

**6.2.8** Determine the half-life of a nuclide from a decay curve.

It is sufficient for students to find a halving-time.

**6.2.9** Solve radioactive decay problems involving integral numbers of half-lives.

**6.3 Nuclear Reactions, Fission and Fusion **

*Nuclear reactions*

**6.3.1** Describe and give an example of artificial (induced) transmutation.

**6.3.2** Construct and complete nuclear reaction equations.

For example,

^{6}*Li*_{3} + ^{1}*n*_{0} = ^{3}*H*_{1} + ^{4}*He*_{2}

**6.3.3** Define the term *unified mass unit*.

**6.3.4** State and apply Einsteins mass-energy equivalence relationship.

**6.3.5** Explain the concepts of mass defect and binding energy.

**6.3.6** Solve problems involving mass defect and binding energies.

*Fission and fusion*

**6.3.7** Describe the processes of nuclear fission and fusion.

Students should be familiar with the concept of a chain reaction.

**6.3.8** Draw and annotate a graph of binding energy per nucleon against atomic number Z, and apply it to predict nuclear energy changes for both the fission and fusion processes.

**6.3.9** State that nuclear fusion is the main source of the Sun's energy.

**6.3.10** Solve problems involving fission and fusion reactions.

For Additional Higher Level Syllabus, **click here**.