Waves and Optics

Properties of Waves - Rectilinear propagation of waves

By the end of the lesson, the learner should be able to:
- Explain the meaning of rectilinear propagation of waves
- Demonstrate rectilinear propagation using sound and light examples
- Relate wave propagation to everyday experiences like torch beams and speaker systems

In groups, learners are guided to:
- Discuss with peers the meaning of rectilinear propagation of waves
- Observe how sound travels from a teacher facing different directions
- Use digital resources to search for applications of rectilinear propagation

How do waves travel from their source?

- Spotlight Physics Grade 10 pg. 147
- Torch
- Digital resources

- Oral questions - Observation - Written assignments

Waves and Optics

Properties of Waves - Reflection of waves
Properties of Waves - Refraction of waves

By the end of the lesson, the learner should be able to:
- Explain the meaning of reflection of waves
- Demonstrate reflection of sound waves using a tall building scenario
- Connect reflection to real-life applications like radar systems and car side mirrors

In groups, learners are guided to:
- Discuss how sound waves bounce off hard surfaces
- Identify applications of reflection in radar, mirrors, and fibre optics
- Use print or non-print media to research reflection applications

Why do we hear echoes near tall buildings?

- Spotlight Physics Grade 10 pg. 148
- Digital resources
- Charts showing reflection
- Spotlight Physics Grade 10 pg. 150
- Glass of water
- Straight object
- Digital resources

- Oral questions - Observation - Group presentations

Waves and Optics

Properties of Waves - Diffraction of waves
Properties of Waves - Interference of waves
Properties of Waves - Demonstrating rectilinear propagation using ripple tank
Properties of Waves - Demonstrating reflection using ripple tank
Properties of Waves - Demonstrating refraction using ripple tank

By the end of the lesson, the learner should be able to:
- Explain the meaning of diffraction of waves
- Demonstrate diffraction using a torch and cone-shaped speaker
- Connect diffraction to how we hear sound around corners and obstacles
- Demonstrate reflection of waves using a ripple tank
- Illustrate reflection patterns with different reflector shapes
- Relate reflection patterns to how car headlamps and satellite dishes work

In groups, learners are guided to:
- Flash a torch at night towards a wall and observe light spreading
- Use a cone-shaped manila paper as a speaker to demonstrate sound diffraction
- Discuss how sound waves bend around obstacles
- Place a straight reflector perpendicular to plane waves and observe
- Place the reflector at an acute angle and record observations
- Use concave and convex reflectors to observe different reflection patterns

How can we hear sound around corners?
How do waves behave when they hit different shaped surfaces?

- Spotlight Physics Grade 10 pg. 151
- Torch
- Manila paper
- Digital resources
- Spotlight Physics Grade 10 pg. 152
- Two identical speakers
- Audio frequency generator
- Spotlight Physics Grade 10 pg. 154
- Ripple tank and accessories
- Dry cell and cell holder
- White manila paper
- Spotlight Physics Grade 10 pg. 156
- Ripple tank
- Straight metal reflector
- Concave and convex reflectors
- Spotlight Physics Grade 10 pg. 158
- Transparent glass plate
- White manila paper

- Oral questions - Observation - Practical demonstration
- Practical assessment - Observation - Written tests

Waves and Optics

Properties of Waves - Demonstrating diffraction using ripple tank
Properties of Waves - Demonstrating interference using ripple tank

By the end of the lesson, the learner should be able to:
- Demonstrate diffraction of waves using a ripple tank
- Investigate how aperture size affects diffraction
- Connect diffraction to how radio waves reach behind buildings

In groups, learners are guided to:
- Place two metal barriers with an aperture in front of plane waves
- Vary the aperture size from 8 cm to 0.5 cm and observe emerging waves
- Place an obstacle in front of waves and observe diffraction around it

What factors determine the extent of wave diffraction?

- Spotlight Physics Grade 10 pg. 159
- Ripple tank
- Two straight metal barriers
- Opaque obstacle
- Spotlight Physics Grade 10 pg. 160
- Two spherical balls
- White manila paper

- Practical assessment - Observation - Written assignments

Waves and Optics

Properties of Waves - Production of frequency modulated (FM) waves

By the end of the lesson, the learner should be able to:
- Explain the meaning of frequency modulation
- Describe methods of producing FM waves
- Connect FM to how radio stations broadcast music and news

In groups, learners are guided to:
- Use digital devices to research the meaning of FM and its production
- Discuss the difference between FM and AM
- Search for applications of frequency modulation

How are FM radio signals produced?

- Spotlight Physics Grade 10 pg. 161
- Digital resources
- Physics reference books

- Oral questions - Written assignments - Group presentations

Waves and Optics

Properties of Waves - Detection of frequency modulated (FM) waves

By the end of the lesson, the learner should be able to:
- Explain how FM waves are detected and demodulated
- Describe applications of FM in various fields
- Relate FM detection to how radios and television sets receive signals

In groups, learners are guided to:
- Discuss demodulation methods for FM signals
- Research applications of FM in radar systems, medical imaging, and telemetry
- Present findings on FM applications to classmates

How do radios detect and convert FM signals to sound?

- Spotlight Physics Grade 10 pg. 162
- Digital resources
- Radio receiver (demonstration)

- Oral questions - Written tests - Research presentations

Waves and Optics

Properties of Waves - Formation of stationary waves
Properties of Waves - Factors affecting fundamental frequency of vibrating string
Properties of Waves - Modes of vibration in strings

By the end of the lesson, the learner should be able to:
- Explain the meaning of stationary waves
- Demonstrate formation of stationary waves using a tuning fork and string
- Connect stationary waves to how guitar strings produce different notes
- Investigate factors affecting fundamental frequency of a vibrating string
- Determine the relationship between frequency, tension, and length
- Relate findings to tuning musical instruments like guitars and violins

In groups, learners are guided to:
- Fix a string to a tuning fork prong and pass over a fixed pulley
- Strike the tuning fork and observe nodes and antinodes
- Discuss how incident and reflected waves superimpose to form stationary waves
- Set up a sonometer apparatus and vary tension while keeping length constant
- Vary the length between bridges while keeping tension constant
- Discuss the mathematical relationship f = (1/2L)√(T/μ)

How are stationary waves formed in a vibrating string?
How do tension and length affect the frequency of a vibrating string?

- Spotlight Physics Grade 10 pg. 163
- Tuning fork
- String
- Mass (weight)
- Fixed pulley system
- Spotlight Physics Grade 10 pg. 164
- Sonometer apparatus
- Weights
- Two wooden wedges
- Spotlight Physics Grade 10 pg. 166
- Digital resources
- Charts showing modes of vibration

- Practical assessment - Observation - Oral questions
- Practical assessment - Written tests - Oral questions

Waves and Optics

Properties of Waves - Stationary waves in closed pipes

By the end of the lesson, the learner should be able to:
- Investigate variation of sound with length of air column in a closed pipe
- Demonstrate resonance in a closed pipe
- Relate closed pipe resonance to how wind instruments like clarinets work

In groups, learners are guided to:
- Dip a glass tube into water and hold a vibrating tuning fork over the open end
- Adjust the tube length until resonance is achieved
- Discuss the relationship between length and wavelength: L = λ/4

How does the length of a closed air column affect the sound produced?

- Spotlight Physics Grade 10 pg. 167
- Glass tube
- Glass jar with water
- Tuning fork

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Harmonics in closed pipes

By the end of the lesson, the learner should be able to:
- Explain harmonics in closed pipes
- Calculate frequencies of overtones in closed pipes
- Connect closed pipe harmonics to the limited overtones in some wind instruments

In groups, learners are guided to:
- Discuss the first harmonic (fundamental frequency) in closed pipes
- Calculate second and third harmonics using f = (2n-1)f₀
- Compare harmonic patterns in closed pipes with open pipes

Why do closed pipes only produce odd harmonics?

- Spotlight Physics Grade 10 pg. 168
- Digital resources
- Charts showing harmonics

- Written tests - Problem-solving exercises - Oral questions

Waves and Optics

Properties of Waves - Stationary waves in open pipes
Properties of Waves - Meaning of Doppler effect

By the end of the lesson, the learner should be able to:
- Explain stationary wave formation in open pipes
- Calculate fundamental frequency and overtones in open pipes
- Relate open pipe resonance to how flutes and organ pipes produce sound

In groups, learners are guided to:
- Discuss how antinodes form at both ends of an open pipe
- Calculate wavelength and frequency relationships: L = λ/2
- Compare fundamental frequencies in open and closed pipes

How do stationary waves form in open pipes?

- Spotlight Physics Grade 10 pg. 169
- Digital resources
- Charts showing open pipe harmonics
- Spotlight Physics Grade 10 pg. 173
- Audio recordings of approaching vehicles

- Written tests - Oral questions - Problem-solving exercises

Waves and Optics

Properties of Waves - Demonstrating Doppler effect
Properties of Waves - Applications of Doppler effect

By the end of the lesson, the learner should be able to:
- Demonstrate Doppler effect using sound sources and ropes
- Observe changes in wavelength when source moves towards or away from observer
- Relate the demonstration to how radar speed guns measure vehicle speed
- Describe applications of Doppler effect in various fields
- Explain how Doppler effect is used in astronomy, medicine, and traffic control
- Connect Doppler applications to ultrasound scans and weather forecasting

In groups, learners are guided to:
- Move an audio frequency generator towards and away from a stationary observer
- Use a rope to show compression and stretching of waves
- Discuss how wavelength decreases when source approaches and increases when receding
- Research applications in astronomy for measuring galaxy movements
- Discuss medical imaging applications like Doppler sonography
- Explore traffic radar and speed camera applications

How does the movement of a sound source affect the waves detected by an observer?
How is Doppler effect used in medicine and traffic control?

- Spotlight Physics Grade 10 pg. 174
- Audio frequency generator
- Rope or spiral spring
- Spotlight Physics Grade 10 pg. 175
- Digital resources
- Charts showing Doppler applications

- Practical assessment - Observation - Oral questions
- Research presentations - Written tests - Oral questions

Waves and Optics

Radioactivity - Meaning of radioactivity and related terms

By the end of the lesson, the learner should be able to:
- Explain the meaning of radioactivity and related terms
- Define nuclear stability, half-life, nuclide, and radioisotope
- Relate radioactivity to smoke detectors and medical treatments

In groups, learners are guided to:
- Use digital resources to search for meanings of radioactivity terms
- Discuss the meaning of radioactive decay, background radiation, and nucleotide
- Share findings with classmates for peer review

What is radioactivity and why do some atoms decay?

- Spotlight Physics Grade 10 pg. 178
- Digital resources
- Physics reference books

- Oral questions - Written assignments - Group discussions

Waves and Optics

Radioactivity - Stability of isotopes and atomic structure
Radioactivity - Types of radiations (alpha, beta, gamma)

By the end of the lesson, the learner should be able to:
- Explain atomic structure in relation to radioactivity
- Describe how neutron-proton ratio affects nuclear stability
- Connect isotope stability to carbon dating of archaeological artifacts

In groups, learners are guided to:
- Discuss the composition of atoms: protons, neutrons, and electrons
- Explain why a 1:1 neutron-proton ratio leads to stability
- Illustrate unstable nuclides using diagrams

How does the neutron-proton ratio affect nuclear stability?

- Spotlight Physics Grade 10 pg. 180
- Digital resources
- Charts showing atomic structure
- Spotlight Physics Grade 10 pg. 181
- Charts showing radiation types

- Written tests - Oral questions - Diagram labelling

Waves and Optics

Radioactivity - Properties of alpha and beta particles

By the end of the lesson, the learner should be able to:
- Describe properties of alpha and beta particles
- Compare penetrating power, ionizing ability, and speed of alpha and beta particles
- Connect alpha radiation properties to smoke detector operation

In groups, learners are guided to:
- Discuss penetrating power: alpha stopped by paper, beta by aluminium
- Compare ionizing power: alpha highest, beta moderate
- Explain deflection in electric and magnetic fields

Why are alpha particles more ionizing but less penetrating than beta particles?

- Spotlight Physics Grade 10 pg. 182
- Digital resources
- Charts comparing radiation properties

- Written tests - Oral questions - Comparison tables

Waves and Optics

Radioactivity - Properties of gamma rays and comparison of radiations
Radioactivity - Alpha decay and nuclear equations

By the end of the lesson, the learner should be able to:
- Describe properties of gamma rays
- Compare all three types of radiations using charts and diagrams
- Relate gamma ray properties to their use in X-ray imaging and cancer treatment
- Write nuclear equations for alpha decay
- Balance nuclear equations showing conservation of mass and charge
- Connect alpha decay to how smoke detectors use americium-241

In groups, learners are guided to:
- Discuss gamma ray properties: no charge, no mass, highest penetration
- Make charts comparing penetrating power, ionizing effect, and field deflection
- Use diagrams to illustrate effect of magnetic and electric fields on radiations
- Discuss how alpha emission reduces nucleon number by 4 and proton number by 2
- Write nuclear equation for radium-226 decaying to radon-222
- Practice balancing nuclear equations

Why are gamma rays not deflected by electric or magnetic fields?
How do we write nuclear equations for alpha decay?

- Spotlight Physics Grade 10 pg. 183
- Digital resources
- Charts and diagrams
- Spotlight Physics Grade 10 pg. 186
- Digital resources
- Periodic table

- Chart making - Written tests - Oral questions
- Written tests - Problem-solving exercises - Oral questions

Waves and Optics

Radioactivity - Beta decay and gamma decay equations
Radioactivity - Uranium-238 decay series

By the end of the lesson, the learner should be able to:
- Write nuclear equations for beta and gamma decay
- Explain how beta decay changes a neutron to a proton
- Relate beta decay to carbon-14 dating of organic materials

In groups, learners are guided to:
- Discuss beta decay: neutron changes to proton and electron
- Write nuclear equation for carbon-14 decaying to nitrogen-14
- Explain gamma decay as energy release without change in mass or atomic number

How do beta and gamma decay differ from alpha decay?

- Spotlight Physics Grade 10 pg. 187
- Digital resources
- Periodic table
- Spotlight Physics Grade 10 pg. 188
- Charts showing decay series
- Digital resources

- Written tests - Problem-solving exercises - Oral questions

Waves and Optics

Radioactivity - Detection using electroscope and GM tube

By the end of the lesson, the learner should be able to:
- Describe detection of radioactive emissions using electroscope
- Explain the structure and operation of a Geiger-Müller tube
- Relate GM tube operation to radiation monitoring in nuclear power plants

In groups, learners are guided to:
- Demonstrate how a charged electroscope loses charge near a radioactive source
- Discuss the components and operation of a GM tube
- Explain how ionization produces pulses counted by a scaler

How does a Geiger-Müller tube detect radiation?

- Spotlight Physics Grade 10 pg. 189
- Electroscope
- Diagrams of GM tube

- Practical demonstration - Oral questions - Written tests

Waves and Optics

Radioactivity - Cloud chambers and nuclear emulsion plates

By the end of the lesson, the learner should be able to:
- Describe detection using expansion and diffusion cloud chambers
- Explain the use of nuclear emulsion plates
- Relate cloud chamber tracks to identifying different radiation types

In groups, learners are guided to:
- Discuss the operation of expansion and diffusion cloud chambers
- Observe track patterns for alpha, beta, and gamma radiations
- Explain how nuclear emulsion plates record particle tracks

How do cloud chambers make radiation tracks visible?

- Spotlight Physics Grade 10 pg. 190
- Diagrams of cloud chambers
- Digital resources

- Diagram interpretation - Written tests - Oral questions

Waves and Optics

Radioactivity - Meaning and demonstration of half-life
Radioactivity - Calculating half-life using graphs and formula
Radioactivity - Significance and applications of half-life

By the end of the lesson, the learner should be able to:
- Explain the meaning of half-life
- Demonstrate half-life concept using water draining from a burette
- Relate half-life to how long radioactive waste remains dangerous
- Calculate half-life from decay curves
- Apply the half-life formula N = N₀(½)^(T/t)
- Connect half-life calculations to determining age of archaeological samples

In groups, learners are guided to:
- Define half-life as time for half the radioactive atoms to decay
- Perform water drainage experiment to simulate radioactive decay
- Plot a graph of volume against time and determine half-life
- Plot decay curves from given data and determine half-life
- Derive and apply the formula N = N₀(½)^(T/t)
- Solve numerical problems involving half-life calculations

How long does it take for half of a radioactive sample to decay?
How do we calculate the half-life of a radioactive substance?

- Spotlight Physics Grade 10 pg. 193
- Burette
- Retort stand
- Stop clock
- Spotlight Physics Grade 10 pg. 195
- Graph paper
- Scientific calculators
- Spotlight Physics Grade 10 pg. 197
- Digital resources
- Physics reference books

- Practical assessment - Graph plotting - Oral questions
- Written tests - Problem-solving exercises - Graph interpretation

Waves and Optics

Radioactivity - Nuclear fission and chain reactions

By the end of the lesson, the learner should be able to:
- Explain the meaning of nuclear fission
- Describe chain reactions in nuclear fission
- Relate nuclear fission to electricity generation in nuclear power plants

In groups, learners are guided to:
- Discuss how uranium-235 splits when bombarded with neutrons
- Explain how chain reactions release enormous energy
- Differentiate controlled reactions in reactors from uncontrolled reactions in bombs

How do nuclear power plants generate electricity from fission?

- Spotlight Physics Grade 10 pg. 198
- Diagrams of chain reactions
- Digital resources

- Written tests - Diagram interpretation - Oral questions

Waves and Optics

Radioactivity - Nuclear fusion and applications

By the end of the lesson, the learner should be able to:
- Explain the meaning of nuclear fusion
- Compare nuclear fusion with fission
- Relate fusion to how the sun and stars produce energy

In groups, learners are guided to:
- Discuss how light nuclei combine to form heavier nuclei
- Explain why fusion requires extremely high temperatures
- Compare energy released in fusion versus fission reactions

Why does nuclear fusion power the sun and stars?

- Spotlight Physics Grade 10 pg. 199
- Diagrams showing fusion
- Digital resources

- Written tests - Comparison tables - Oral questions

Waves and Optics

Radioactivity - Applications in medicine and industry

By the end of the lesson, the learner should be able to:
- Describe applications of radioactivity in medicine and industry
- Explain how gamma rays treat cancer and sterilize equipment
- Relate industrial applications to detecting pipe leaks and measuring thickness

In groups, learners are guided to:
- Discuss medical applications: cancer treatment, sterilization, imaging
- Explain industrial uses: detecting pipe bursts, thickness measurement, flaw detection
- Research use of radioactive tracers in various fields

How is radioactivity used to treat cancer and detect pipe leaks?

- Spotlight Physics Grade 10 pg. 200
- Diagrams showing applications
- Digital resources

- Research presentations - Written tests - Oral questions

Waves and Optics
Electricity and Magnetism

Radioactivity - Applications in agriculture and archaeology
Radioactivity - Hazards of radiation and safety precautions
Origin of charges in a material
The law of electrostatics

By the end of the lesson, the learner should be able to:
- Describe applications of radioactivity in agriculture and archaeology
- Explain carbon dating principles
- Relate radioactive tracers to studying plant fertilizer absorption
- Define electric charge and state its SI unit
- Describe the atomic structure and origin of charges in materials
- Relate static electricity to everyday experiences like clothes clinging after tumble drying

In groups, learners are guided to:
- Discuss carbon dating for determining age of fossils and artifacts
- Explain use of radioactive tracers in agriculture
- Calculate ages using carbon-14 decay principles
- Discuss with peers the origin of charges on materials (atom, nucleus, neutrons, protons and electrons)
- Use digital resources to search for information on atomic structure
- Perform experiments to demonstrate generation of static charges through rubbing plastic pen on woolen cloth

How do scientists use carbon dating to determine the age of fossils?
How do materials acquire electric charges?

- Spotlight Physics Grade 10 pg. 200
- Digital resources
- Charts on carbon dating
- Spotlight Physics Grade 10 pg. 201
- Safety signs
- Digital resources
- Spotlight Physics Learner's Book pg. 205
- Plastic pen, woolen cloth
- Small pieces of paper
- Digital resources
- Spotlight Physics Learner's Book pg. 207
- Balloons, woolen cloth
- Thread, retort stands
- Metre rule

- Written tests - Problem-solving - Oral questions
- Oral questions - Observation - Written assignments

Electricity and Magnetism

Methods of charging conductors - Induction and Contact
Methods of charging conductors - Separation and charge distribution
Electric field patterns

By the end of the lesson, the learner should be able to:
- Explain charging by induction and contact methods
- Demonstrate charging conductors using induction and contact
- Relate induction charging to wireless phone charging technology

In groups, learners are guided to:
- Discuss with peers the induction and contact methods of charging
- Perform experiments to charge metallic spheres by induction and contact
- Sketch charge distribution during each stage
- Compare the two methods of charging

How can a conductor be charged without losing charge from the charging rod?

- Spotlight Physics Learner's Book pg. 208
- Metallic spheres on insulated stands
- Charged polythene and glass rods
- Connecting wire for earthing
- Spotlight Physics Learner's Book pg. 211
- Two metallic spheres on insulated stands
- Charged rods
- Charts showing charge distribution
- Spotlight Physics Learner's Book pg. 214
- Charts showing electric field patterns
- Digital resources
- Drawing materials

- Practical assessment - Oral questions - Diagram sketching

Electricity and Magnetism

The electroscope - Structure, charging and discharging
Uses of electroscope
Applications - Spray painting, precipitators and photocopiers

By the end of the lesson, the learner should be able to:
- Identify and explain functions of parts of a gold-leaf electroscope
- Demonstrate charging an electroscope by induction and contact
- Connect electroscope principles to static charge detectors in industry

In groups, learners are guided to:
- Study the various parts of the electroscope and their functions
- Carry out activities to charge an electroscope by induction and contact
- Demonstrate earthing/discharging of an electroscope
- Construct a simple electroscope using locally available materials

How does the leaf of an electroscope respond to charging?

- Spotlight Physics Learner's Book pg. 216
- Gold-leaf electroscope
- Charged polythene and glass rods
- Conical flask, aluminium foil, metal spoon
- Spotlight Physics Learner's Book pg. 219
- Various charged materials
- Conductors and insulators for testing
- Spotlight Physics Learner's Book pg. 221
- Charts and diagrams
- Digital resources
- Videos on spray painting

- Practical assessment - Observation - Oral questions

Electricity and Magnetism

Applications - Lightning arrestors and safety measures

By the end of the lesson, the learner should be able to:
- Explain the design and function of lightning arrestors
- Describe safety measures in transportation of flammable substances
- Relate lightning arrestors to protection of buildings during thunderstorms

In groups, learners are guided to:
- Discuss the design and function of lightning arrestors
- Explain why metallic chains are attached to fuel tankers
- Research safety in transportation of flammable liquids and gases
- Discuss why people should not stand under trees during storms

Why are lightning arrestors installed on tall buildings?

- Spotlight Physics Learner's Book pg. 223
- Pictures of lightning arrestors
- Charts on safety measures
- Digital resources

- Oral questions - Written assignments - Group discussions

Electricity and Magnetism

Applications - Touch screens, fingerprinting and capacitors
Current and potential difference
Electromotive force and internal resistance
Ohm's law - Verification and calculations
EMF equation and internal resistance determination

By the end of the lesson, the learner should be able to:
- Explain electrostatic applications in touch screens and fingerprinting
- Describe the role of electrostatics in capacitors
- Connect capacitive touch technology to everyday smartphone use
- State and verify Ohm's law experimentally
- Apply Ohm's law equation V = IR to solve problems
- Connect Ohm's law to selecting appropriate fuses for home appliances

In groups, learners are guided to:
- Discuss the principle behind capacitive touch screens
- Research on electrostatic fingerprinting and live scanning
- Explain how capacitors in electronic devices use electrostatic principles
- Explore air purifiers and other applications
- Set up circuit with nichrome wire, ammeter, voltmeter and rheostat
- Vary current and record corresponding voltages
- Plot graph of V against I and determine resistance from gradient
- Solve numerical problems using V = IR

How do smartphones detect finger touches using electrostatics?
What is the relationship between voltage and current for an ohmic conductor?

- Spotlight Physics Learner's Book pg. 225
- Smartphones and tablets
- Digital resources
- Charts on touch screen technology
- Spotlight Physics Learner's Book pg. 228
- Dry cells, cell holders
- Ammeter, voltmeter, bulb
- Connecting wires, switch
- Spotlight Physics Learner's Book pg. 231
- Dry cells, two voltmeters
- Known resistors, switch
- Connecting wires
- Spotlight Physics Learner's Book pg. 232
- Nichrome wire, ammeter
- Voltmeter, rheostat
- Dry cells, graph paper
- Spotlight Physics Learner's Book pg. 236
- Dry cells, ammeter
- Graph paper

- Oral questions - Written tests - Research presentations
- Practical assessment - Graph plotting - Written calculations

Electricity and Magnetism

Ohmic and non-ohmic conductors
Factors affecting resistance - Length and cross-sectional area
Factors affecting resistance - Temperature and resistivity

By the end of the lesson, the learner should be able to:
- Classify conductors as ohmic or non-ohmic based on V-I characteristics
- Investigate V-I relationship of torch bulb, thermistor and diode
- Relate non-ohmic behaviour to why bulbs are dim when first switched on

In groups, learners are guided to:
- Investigate V-I relationship of different conductors
- Draw I-V characteristic graphs for tungsten, torch bulb, thermistor and diode
- Classify conductors based on their graphs
- Compare behaviour of ohmic and non-ohmic conductors

Why do some conductors not obey Ohm's law?

- Spotlight Physics Learner's Book pg. 242
- Torch bulb, thermistor
- Semiconductor diode
- Ammeter, voltmeter, rheostat
- Spotlight Physics Learner's Book pg. 245
- Nichrome wire, metre rule
- Wires of different thickness
- Micrometer screw gauge, ammeter, voltmeter
- Spotlight Physics Learner's Book pg. 248
- Tungsten coil, beaker
- Thermometer, heat source
- Ammeter, voltmeter

- Practical assessment - Graph plotting - Oral questions

Electricity and Magnetism

Methods of determining resistance
Types of resistors and current-voltage laws

By the end of the lesson, the learner should be able to:
- Determine resistance using voltmeter-ammeter, metre bridge and Wheatstone bridge methods
- Read resistance values using colour codes
- Apply different methods to verify resistor values in electronic repair

In groups, learners are guided to:
- Determine resistance using V-A method and calculate from R = V/I
- Set up metre bridge to find unknown resistance using K/Y = P/Q
- Connect Wheatstone bridge and calculate using K/P = L/Q
- Read resistance from colour bands on resistors

Which method is most accurate for measuring resistance?

- Spotlight Physics Learner's Book pg. 251
- Metre bridge, Wheatstone bridge components
- Galvanometer, jockey
- Resistors with colour codes
- Spotlight Physics Learner's Book pg. 255
- Various types of resistors
- Identical bulbs, ammeters
- Voltmeters, dry cells

- Practical assessment - Written calculations - Identification exercises

Electricity and Magnetism

Effective resistance in series and parallel

By the end of the lesson, the learner should be able to:
- Derive and apply formulas for effective resistance in series and parallel
- Calculate effective resistance in mixed circuits
- Apply resistance calculations to design circuits for specific purposes

In groups, learners are guided to:
- Derive R_T = R₁ + R₂ + R₃ for series circuits
- Derive 1/R_T = 1/R₁ + 1/R₂ + 1/R₃ for parallel circuits
- Solve problems involving series, parallel and combination circuits
- Calculate current and voltage in each resistor

How do we calculate total resistance in series and parallel circuits?

- Spotlight Physics Learner's Book pg. 263
- Resistors of known values
- Scientific calculators
- Circuit diagrams, worksheets

- Written calculations - Problem-solving tests - Oral questions

Electricity and Magnetism

Solving complex resistor network problems
Relationship of V, I and P - Power equations
Factors affecting heating effect of electric current

By the end of the lesson, the learner should be able to:
- Analyse circuits with multiple series-parallel combinations
- Calculate current through and voltage across each resistor
- Apply circuit analysis to troubleshoot electrical faults in appliances
- Derive and apply power equations P = VI, P = I²R and P = V²/R
- Calculate power consumption of electrical devices
- Relate power ratings to energy efficiency of household appliances

In groups, learners are guided to:
- Identify series and parallel sections in complex circuits
- Calculate effective resistance step by step
- Determine current distribution in branches
- Calculate potential difference across each component
- Discuss electrical power as rate of energy conversion
- Derive power equations from P = W/t and Ohm's law
- Calculate power in circuits using different formulas
- Compare power ratings of various appliances

How do we analyse circuits with both series and parallel resistors?
What is the relationship between voltage, current and power?

- Spotlight Physics Learner's Book pg. 267
- Complex circuit diagrams
- Scientific calculators
- Worksheets with problems
- Spotlight Physics Learner's Book pg. 270
- Scientific calculators
- Power rating labels from appliances
- Worksheets
- Spotlight Physics Learner's Book pg. 273
- Heating coils, beaker
- Thermometer, stopwatch
- Ammeter, voltmeter, rheostat

- Written calculations - Circuit analysis - Oral questions
- Written calculations - Oral questions - Problem-solving tests

Electricity and Magnetism

Applications of heating effect of electric current

By the end of the lesson, the learner should be able to:
- Describe applications of heating effect in electrical appliances
- Explain the working of electric heaters, kettles, iron boxes and fuses
- Relate heating applications to safe and efficient use of electrical devices at home

In groups, learners are guided to:
- Research on electrical appliances that use heating effect
- Classify appliances as heating devices, kitchenware or lighting devices
- Discuss the working of electric iron, kettle, heater and filament lamp
- Explain the function and selection of appropriate fuses

How is the heating effect of electric current applied in household appliances?

- Spotlight Physics Learner's Book pg. 277
- Pictures of electrical appliances
- Fuses of different ratings
- Digital resources

- Oral questions - Written assignments - Research presentations

Electricity and Magnetism

Power rating and electrical energy calculations

By the end of the lesson, the learner should be able to:
- Interpret power ratings on electrical appliances
- Calculate electrical energy consumption using E = Pt
- Apply energy calculations to reduce electricity bills at home

In groups, learners are guided to:
- Read and interpret power ratings on appliance labels
- Calculate energy consumed in joules and kilowatt-hours
- Calculate cost of running appliances using electricity tariffs
- Discuss energy-saving practices

How do we calculate the cost of running electrical appliances?

- Spotlight Physics Learner's Book pg. 278
- Power rating labels
- Scientific calculators
- Electricity tariff information

- Written calculations - Oral questions - Problem-solving tests