Refraction of Light

Introduction to Refraction and Basic Phenomena
Laws of Refraction and Snell's Law

By the end of the lesson, the learner should be able to:
Define refraction of light
-Explain why light bends when passing from one medium to another
-Identify examples of refraction in daily life
-Distinguish between optically dense and optically rare media
-Describe the behavior of light at interfaces
State the two laws of refraction
-Define refractive index and state its symbol
-Apply Snell's law: sin i/sin r = constant
-Understand that incident ray, refracted ray and normal lie in same plane
-Calculate refractive index from experimental data

Q/A on light behavior students observe daily
-Demonstration: stick in water appearing bent
-Demonstration: coin in beaker appearing raised
-Discussion on swimming pool appearing shallow
-Observation of refraction using glass block and pins
-Drawing ray diagrams showing refraction
-Safety precautions when handling glass
Review refraction phenomena through Q/A
-Experiment: investigating refraction through glass block
-Measuring angles of incidence and refraction
-Plotting graph of sin i against sin r
-Derivation and application of Snell's law
-Worked examples calculating refractive index
-Discussion on significance of constant ratio

Glass blocks
-Beakers
-Water
-Coins
-Sticks/pencils
-Pins
-White paper
-Ray box (if available)
-Charts showing refraction examples
Glass blocks
-Pins
-Protractor
-Ruler
-White paper
-Graph paper
-Calculator
-Ray box
-Soft board
-Drawing pins

KLB Secondary Physics Form 3, Pages 33-35
KLB Secondary Physics Form 3, Pages 35-39

Refraction of Light

Absolute and Relative Refractive Index

By the end of the lesson, the learner should be able to:
Define absolute and relative refractive index
-Relate refractive index to speed of light in different media
-Apply the relationship n = c/v
-Calculate relative refractive index between two media
-Solve problems involving refractive indices

Q/A review on Snell's law and calculations
-Discussion on light speed in different media
-Derivation of n = c/v relationship
-Explanation of absolute vs relative refractive index
-Worked examples with multiple media
-Problem-solving session with real materials
-Group work on refractive index calculations

Calculator
-Charts showing refractive indices
-Worked examples
-Reference tables
-Graph paper
-Different transparent materials
-Speed of light reference chart

KLB Secondary Physics Form 3, Pages 39-43

Refraction of Light

Real and Apparent Depth

By the end of the lesson, the learner should be able to:
Explain why objects under water appear nearer than actual position
-Define real depth, apparent depth and vertical displacement
-Derive the relationship n = real depth/apparent depth
-Calculate apparent depth and vertical displacement
-Apply concepts to practical situations

Review refractive index through Q/A
-Demonstration: coin at bottom of beaker appears raised
-Experiment: measuring real and apparent depth
-Derivation of n = real depth/apparent depth
-Worked examples on swimming pools, tanks
-Practical: determining apparent depth using travelling microscope method
-Discussion on viewing angle effects

Beakers
-Water
-Coins
-Rulers
-Pins
-Travelling microscope (if available)
-Glass blocks
-Colored chalk dust
-Calculator
-Measuring cylinders

KLB Secondary Physics Form 3, Pages 44-48

Refraction of Light

Experimental Determination of Refractive Index

By the end of the lesson, the learner should be able to:
Describe methods to determine refractive index experimentally
-Use real and apparent depth method
-Apply pin method for refractive index determination
-Use no-parallax method
-Calculate refractive index from experimental data
-Discuss sources of error and precautions

Q/A on real and apparent depth concepts
-Experiment 1: Real and apparent depth using pins
-Experiment 2: Glass block method using pins
-Experiment 3: No-parallax method with water
-Data collection and analysis
-Plotting graphs where applicable
-Discussion on experimental errors and improvements

Glass blocks
-Pins
-Cork holders
-Beakers
-Water
-Rulers
-White paper
-Clamp and stand
-Graph paper
-Calculator
-Measuring tape

KLB Secondary Physics Form 3, Pages 48-51

Refraction of Light

Critical Angle and Total Internal Reflection
Applications of Total Internal Reflection - Optical Devices

By the end of the lesson, the learner should be able to:
Define critical angle
-State conditions for total internal reflection
-Derive relationship between critical angle and refractive index
-Calculate critical angle for different materials
-Explain total internal reflection using ray diagrams
Explain working of periscope using total internal reflection
-Describe use of prisms in optical instruments
-Understand principle of optical fibers
-Explain advantages of prisms over mirrors
-Analyze light paths in prism binoculars and pentaprism

Review experimental methods through Q/A
-Demonstration: increasing angle of incidence in glass-air interface
-Observation of critical angle and total internal reflection
-Derivation of sin c = 1/n relationship
-Worked examples calculating critical angles
-Investigation using semi-circular glass block
-Discussion on applications of total internal reflection
Q/A review on critical angle and TIR
-Demonstration: 45° prisms turning light through 90° and 180°
-Construction of simple periscope model
-Explanation of optical fiber principle
-Discussion on prism binoculars and pentaprism
-Comparison of prisms vs mirrors advantages
-Practical: observing TIR in water-filled apparatus

Semi-circular glass block
-Ray box
-White paper
-Protractor
-Pins
-Calculator
-Charts showing TIR
-Water
-Different transparent blocks
45° prisms
-Periscope model
-Optical fiber samples
-Mirrors for comparison
-Ray box
-Water
-Transparent containers
-Charts showing optical instruments
-Binoculars (if available)

KLB Secondary Physics Form 3, Pages 51-55
KLB Secondary Physics Form 3, Pages 55-58

Refraction of Light

Mirage and Atmospheric Refraction
Dispersion of White Light

By the end of the lesson, the learner should be able to:
Explain formation of mirage using refraction principles
-Describe atmospheric refraction effects
-Understand continuous refraction in varying density media
-Explain why sun appears above horizon after sunset
-Discuss polar mirages and their formation

Review TIR applications through Q/A
-Demonstration of refraction in liquids of different densities
-Explanation of hot air effects on light path
-Discussion on desert mirages and road mirages
-Atmospheric refraction effects on sun position
-Analysis of continuous refraction in varying media
-Drawing ray diagrams for mirage formation

Liquids of different densities
-Transparent containers
-Heat source (safe)
-Charts showing mirage formation
-Diagrams of atmospheric refraction
-Pictures of mirages
-Ray diagrams
Triangular glass prism
-White light source
-Screen
-Ray box
-CD/DVD
-White paper
-Ruler
-Charts showing spectrum
-Pictures of rainbows

KLB Secondary Physics Form 3, Pages 55-56

Refraction of Light

Recombination of Spectrum and Problem Solving

By the end of the lesson, the learner should be able to:
Demonstrate recombination of dispersed light
-Explain Newton's disc experiment
-Use concave mirror to recombine spectrum
-Solve complex problems involving refraction
-Apply all refraction concepts to examination-type questions

Review dispersion concepts through Q/A
-Experiment: recombining spectrum using second prism
-Demonstration of Newton's disc
-Using concave mirror to focus spectrum
-Comprehensive problem-solving session covering all topics
-Practice with past examination questions
-Review and consolidation of entire unit

Second triangular prism
-Concave mirror
-Newton's disc
-Motor (for spinning disc)
-Calculator
-Past exam papers
-Comprehensive problem sets
-Review charts
-All previous apparatus for revision

KLB Secondary Physics Form 3, Pages 58-60

Work, Energy, Power and Machines

Sources of Energy

By the end of the lesson, the learner should be able to:
Identify different sources of energy
-Distinguish between renewable and non-renewable energy sources
-Classify energy sources into appropriate categories
-Discuss advantages and disadvantages of different energy sources
-Understand energy crisis and conservation needs

Q/A on energy experiences in daily life
-Discussion on various energy sources students know
-Classification activity: renewable vs non-renewable
-Group work on energy source advantages/disadvantages
-Presentation on local energy sources in Kenya
-Discussion on energy conservation importance

Charts showing energy sources
-Pictures of solar panels, wind mills
-Samples: coal, wood, batteries
-Energy source classification cards
-Local energy examples
-Conservation posters

KLB Secondary Physics Form 3, Pages 93-95

Work, Energy, Power and Machines

Forms of Energy
Energy Transformation and Conservation

By the end of the lesson, the learner should be able to:
Define different forms of energy
-Identify chemical, mechanical, heat, electrical, and wave energy
-Give examples of each form of energy
-Understand energy exists in various forms
-Relate forms of energy to daily experiences
Understand energy transformations between different forms
-State the law of conservation of energy
-Identify transducers and their functions
-Apply conservation of energy to various situations
-Draw energy transformation diagrams

Review energy sources through Q/A
-Introduction to different forms of energy
-Demonstration: chemical energy in battery, mechanical energy in moving objects
-Discussion on heat energy from friction
-Examples of electrical energy in appliances
-Identification of wave energy: light, sound
Q/A on forms of energy
-Demonstration: energy transformations in hydroelectric power
-Examples of transducers: battery, dynamo, solar cell
-Statement and explanation of energy conservation law
-Drawing energy flow diagrams
-Discussion on energy losses and efficiency

Battery and bulb
-Moving trolley
-Rubbing blocks for friction
-Electrical appliances
-Tuning fork
-Torch
-Energy forms charts
-Real objects showing energy forms
Dynamo
-Battery
-Solar cell (if available)
-Charts showing energy transformations
-Transducer examples
-Energy flow diagrams
-Hydroelectric model setup

KLB Secondary Physics Form 3, Pages 95-96
KLB Secondary Physics Form 3, Pages 96-97

Work, Energy, Power and Machines

Work and its Calculation

By the end of the lesson, the learner should be able to:
Define work in scientific terms
-State the condition for work to be done
-Calculate work using W = F × d
-Understand work as a scalar quantity
-Solve problems involving work calculations

Review energy transformations through Q/A
-Definition of work with emphasis on force and displacement
-Demonstration: lifting objects, pushing trolleys
-Worked examples on work calculations
-Discussion on when no work is done
-Problem-solving session on work calculations

Spring balance
-Masses
-Trolley
-Measuring tape
-Calculator
-Force and displacement demonstrations
-Worked examples charts
-Problem worksheets

KLB Secondary Physics Form 3, Pages 96-99

Work, Energy, Power and Machines

Work with Variable Forces
Gravitational Potential Energy

By the end of the lesson, the learner should be able to:
Calculate work done by variable forces
-Interpret force-distance graphs
-Find work done using area under graphs
-Understand positive and negative work
-Apply graphical methods to work calculations

Q/A review on work calculations
-Introduction to variable forces
-Plotting force-distance graphs
-Demonstration: stretching spring with varying force
-Calculation of areas under graphs
-Worked examples with triangular and trapezoidal areas

Graph paper
-Springs
-Force meter
-Ruler
-Calculator
-Force-distance graph examples
-Different shaped area examples
-Demonstration springs
Masses of different sizes
-Measuring tape
-Spring balance
-Height measurement setup
-Worked examples
-Gravitational P.E. charts

KLB Secondary Physics Form 3, Pages 99-100

Work, Energy, Power and Machines

Kinetic Energy

By the end of the lesson, the learner should be able to:
Define kinetic energy
-Derive K.E. = ½mv²
-Calculate kinetic energy of moving objects
-Understand relationship between work and kinetic energy
-Apply work-energy theorem

Q/A on potential energy concepts
-Demonstration: moving trolleys at different speeds
-Derivation of K.E. = ½mv² using work-energy theorem
-Worked examples on kinetic energy calculations
-Discussion on work-energy theorem
-Problem-solving session on kinetic energy

Trolleys
-Stopwatch
-Measuring tape
-Spring balance
-Calculator
-Kinetic energy demonstration setup
-Speed measurement apparatus

KLB Secondary Physics Form 3, Pages 102-105

Work, Energy, Power and Machines

Conservation of Mechanical Energy
Power and its Applications

By the end of the lesson, the learner should be able to:
Apply conservation of energy to mechanical systems
-Analyze energy changes in pendulums and projectiles
-Solve problems using conservation of energy
-Understand energy transformations in oscillating systems
-Calculate energy at different positions
Define power as rate of doing work
-Calculate power using P = W/t and P = Fv
-State SI unit of power (Watt)
-Understand power ratings of appliances
-Solve problems involving power calculations

Review kinetic energy through Q/A
-Demonstration: simple pendulum energy changes
-Analysis of energy at different positions in pendulum swing
-Discussion on energy conservation in projectile motion
-Worked examples using conservation of energy
-Problem-solving on energy conservation
Q/A on energy conservation
-Definition of power with examples
-Derivation of P = W/t and P = Fv
-Discussion on power ratings of electrical appliances
-Worked examples on power calculations
-Investigation: measuring power of students climbing stairs

Simple pendulum setup
-Measuring tape
-Stopwatch
-Masses
-Calculator
-Pendulum energy charts
-Conservation examples
-String and bob
Stopwatch
-Measuring tape
-Spring balance
-Calculator
-Electrical appliances for power ratings
-Stairs for practical work
-Power calculation charts

KLB Secondary Physics Form 3, Pages 104-106
KLB Secondary Physics Form 3, Pages 106-108

Work, Energy, Power and Machines

Simple Machines - Introduction and Terminology

By the end of the lesson, the learner should be able to:
Define machines and their purposes
-Understand load, effort, and fulcrum
-Define mechanical advantage, velocity ratio, and efficiency
-Calculate M.A., V.R., and efficiency
-Understand relationship between these quantities

Review power concepts through Q/A
-Introduction to machines and their uses
-Demonstration: simple lever showing load, effort, fulcrum
-Definition and calculation of M.A., V.R., and efficiency
-Worked examples on machine calculations
-Discussion on why efficiency is always less than 100%

Simple lever setup
-Masses for loads
-Spring balance
-Ruler
-Calculator
-Machine terminology charts
-Efficiency calculation examples

KLB Secondary Physics Form 3, Pages 108-112

Work, Energy, Power and Machines

Levers - Types and Applications

By the end of the lesson, the learner should be able to:
Classify levers into three types
-Identify examples of each type of lever
-Apply principle of moments to levers
-Calculate forces in lever systems
-Understand applications of different lever types

Q/A on machine terminology
-Classification of levers: Class I, II, and III
-Demonstration: examples of each lever type
-Application of principle of moments
-Worked examples on lever calculations
-Identification of levers in daily life tools

Various lever examples
-Rulers
-Masses
-Spring balance
-Fulcrum supports
-Lever classification charts
-Daily life lever examples
-Calculator

KLB Secondary Physics Form 3, Pages 112-114

Work, Energy, Power and Machines

Pulleys - Fixed and Movable

By the end of the lesson, the learner should be able to:
Understand operation of fixed and movable pulleys
-Calculate M.A. and V.R. for different pulley systems
-Analyze block and tackle arrangements
-Solve problems involving pulley systems
-Understand advantages of pulley systems

Review lever types through Q/A
-Demonstration: fixed pulley operation
-Demonstration: single movable pulley
-Analysis of block and tackle systems
-Calculation of M.A. and V.R. for different arrangements
-Problem-solving on pulley systems

Pulley blocks
-String
-Masses
-Spring balance
-Pulley arrangements
-Block and tackle setup
-Calculator
-Pulley system diagrams

KLB Secondary Physics Form 3, Pages 115-120

Work, Energy, Power and Machines

Inclined Planes and Screws
Gears and Hydraulic Systems
Efficiency of Machines

By the end of the lesson, the learner should be able to:
Understand inclined plane as a machine
-Calculate M.A. and V.R. for inclined planes
-Analyze screw as an inclined plane
-Understand applications of inclined planes
-Solve problems involving inclined planes
Understand factors affecting machine efficiency
-Calculate efficiency using different methods
-Investigate efficiency of various machines
-Understand energy losses in machines
-Discuss methods to improve efficiency

Q/A on pulley systems
-Demonstration: moving load up inclined plane
-Measurement of effort and load for inclined plane
-Calculation of M.A. and V.R. for inclined plane
-Discussion on screw as modified inclined plane
-Examples of inclined planes in daily life
Q/A on gears and hydraulic systems
-Investigation: efficiency of pulley system
-Discussion on factors causing energy losses
-Measurement of input and output work
-Calculation of efficiency for different machines
-Discussion on improving machine efficiency

Inclined plane setup
-Trolley or wooden block
-Spring balance
-Measuring tape
-Protractor
-Calculator
-Screw examples
-Various inclined plane models
Gear wheels
-Bicycle for gear demonstration
-Syringes of different sizes
-Water
-Tubes
-Hydraulic system diagrams
-Gear ratio charts
Various machines for testing
-Spring balances
-Measuring tape
-Stopwatch
-Calculator
-Efficiency measurement setup
-Lubricants for demonstration

KLB Secondary Physics Form 3, Pages 114-115
KLB Secondary Physics Form 3, Pages 120-123

Current Electricity (II)

Electric Current and Measurement

By the end of the lesson, the learner should be able to:
Define electric current and state its SI unit
-Understand conventional current flow
-Use ammeters correctly to measure current
-Read ammeter scales accurately
-Understand current as rate of flow of charge

Q/A review on basic electricity from Form 2
-Definition of electric current and conventional flow
-Demonstration: proper ammeter connection in series
-Practice reading different ammeter scales
-Discussion on digital vs analogue meters
-Safety precautions when using electrical equipment

Ammeters (analogue and digital)
-Dry cells
-Connecting wires
-Bulbs
-Switches
-Ammeter scale charts
-Safety equipment

KLB Secondary Physics Form 3, Pages 126-130

Current Electricity (II)

Series and Parallel Circuits - Current Distribution

By the end of the lesson, the learner should be able to:
Investigate current in series circuits
-Investigate current in parallel circuits
-Apply Kirchhoff's current law
-Understand current division in parallel circuits
-Solve problems involving current distribution

Review ammeter usage through Q/A
-Experiment: measuring current in series circuit
-Experiment: measuring current in parallel circuit
-Analysis of current readings and patterns
-Statement of Kirchhoff's current law
-Problem-solving on current distribution

Multiple ammeters
-Bulbs
-Connecting wires
-Dry cells
-Switches
-Circuit boards
-Calculator
-Current distribution worksheets

KLB Secondary Physics Form 3, Pages 130-133

Current Electricity (II)

Potential Difference and Voltage Measurement

By the end of the lesson, the learner should be able to:
Define potential difference in terms of work done
-State the SI unit of potential difference
-Use voltmeters correctly to measure voltage
-Understand voltage measurement across components
-Read voltmeter scales accurately

Q/A on current distribution
-Definition of potential difference and work done per unit charge
-Demonstration: proper voltmeter connection in parallel
-Practice measuring voltage across different components
-Comparison of voltmeter and ammeter connections
-Safety considerations in voltage measurement

Voltmeters (analogue and digital)
-Dry cells
-Resistors
-Bulbs
-Connecting wires
-Switches
-Voltmeter scale charts
-Work and charge demonstration materials

KLB Secondary Physics Form 3, Pages 126-129

Current Electricity (II)

Series and Parallel Circuits - Voltage Distribution
Ohm's Law - Investigation and Verification

By the end of the lesson, the learner should be able to:
Investigate voltage in series circuits
-Investigate voltage in parallel circuits
-Apply Kirchhoff's voltage law
-Understand voltage division in series circuits
-Solve problems involving voltage distribution
State Ohm's law
-Investigate relationship between voltage and current
-Plot V-I graphs for ohmic conductors
-Verify Ohm's law experimentally
-Understand conditions for Ohm's law validity

Review voltage measurement through Q/A
-Experiment: measuring voltage across series components
-Experiment: measuring voltage across parallel components
-Analysis of voltage readings and patterns
-Statement of Kirchhoff's voltage law
-Problem-solving on voltage distribution
Q/A on voltage distribution
-Experiment: varying voltage and measuring current through resistor
-Data collection and table completion
-Plotting V-I graph and analyzing slope
-Statement and verification of Ohm's law
-Discussion on temperature and other conditions

Multiple voltmeters
-Various resistors
-Connecting wires
-Dry cells
-Switches
-Circuit boards
-Calculator
-Voltage distribution worksheets
Rheostat
-Ammeter
-Voltmeter
-Resistor coils
-Connecting wires
-Dry cells
-Graph paper
-Calculator
-Ruler

KLB Secondary Physics Form 3, Pages 130-133
KLB Secondary Physics Form 3, Pages 131-135

Current Electricity (II)

Electrical Resistance and Ohm's Law Applications
Ohmic and Non-Ohmic Conductors

By the end of the lesson, the learner should be able to:
Define electrical resistance and its SI unit
-Apply Ohm's law to calculate V, I, and R
-Understand the relationship R = V/I
-Solve problems using Ohm's law
-Convert between different units of resistance

Review Ohm's law investigation through Q/A
-Definition of electrical resistance as V/I ratio
-Worked examples applying Ohm's law triangle
-Unit conversions: Ω, kΩ, MΩ
-Problem-solving session on Ohm's law calculations
-Discussion on factors affecting resistance

Calculator
-Ohm's law triangle charts
-Resistor color code charts
-Various resistors
-Multimeter
-Problem worksheets
-Unit conversion charts
Filament bulbs
-Diodes
-Thermistors
-LDR
-Ammeter
-Voltmeter
-Rheostat
-Graph paper
-Various conductors for testing

KLB Secondary Physics Form 3, Pages 131-135

Current Electricity (II)

Types of Resistors and Their Applications

By the end of the lesson, the learner should be able to:
Identify different types of resistors
-Understand fixed and variable resistors
-Read resistor color codes
-Understand applications of special resistors
-Use rheostats and potentiometers

Review ohmic vs non-ohmic conductors through Q/A
-Identification of resistor types: carbon, wire-wound, variable
-Practice reading resistor color codes
-Demonstration: rheostat and potentiometer operation
-Discussion on thermistors and LDR applications
-Practical applications in circuits

Various resistor types
-Color code charts
-Rheostat
-Potentiometer
-Thermistor
-LDR
-Multimeter
-Circuit boards
-Application examples

KLB Secondary Physics Form 3, Pages 135-140

Current Electricity (II)

Measurement of Resistance - Voltmeter-Ammeter Method

By the end of the lesson, the learner should be able to:
Describe voltmeter-ammeter method
-Set up circuits for resistance measurement
-Calculate resistance from V and I readings
-Understand limitations of the method
-Analyze experimental errors

Q/A on resistor types
-Setup of voltmeter-ammeter circuit
-Measurement of voltage and current for unknown resistor
-Calculation of resistance using R = V/I
-Discussion on measurement errors and accuracy
-Comparison with multimeter readings

Unknown resistors
-Voltmeter
-Ammeter
-Rheostat
-Connecting wires
-Dry cells
-Switches
-Calculator
-Multimeter for comparison

KLB Secondary Physics Form 3, Pages 140-142

Current Electricity (II)

Wheatstone Bridge Method
Resistors in Series - Theory and Calculations

By the end of the lesson, the learner should be able to:
Understand the principle of Wheatstone bridge
-Set up Wheatstone bridge circuit
-Balance the bridge for resistance measurement
-Calculate unknown resistance using bridge equation
-Appreciate accuracy of Wheatstone bridge method
Derive formula for resistors in series
-Calculate total resistance for series combination
-Understand current and voltage in series circuits
-Solve problems involving series resistors
-Apply series resistance in circuit analysis

Review voltmeter-ammeter method through Q/A
-Introduction to Wheatstone bridge principle
-Demonstration of bridge balance condition
-Setup and operation of Wheatstone bridge
-Calculation using R₁/R₂ = R₃/R₄
-Comparison of accuracy with other methods
Q/A on resistance measurement methods
-Derivation of Rs = R₁ + R₂ + R₃...
-Demonstration: measuring total resistance of series combination
-Analysis of current (same) and voltage (divided) in series
-Worked examples on series resistance calculations
-Problem-solving session

Wheatstone bridge apparatus
-Galvanometer
-Known resistors
-Unknown resistors
-Connecting wires
-Battery
-Calculator
-Bridge equation charts
Resistors of known values
-Multimeter
-Connecting wires
-Circuit boards
-Calculator
-Series circuit diagrams
-Problem worksheets

KLB Secondary Physics Form 3, Pages 142-144
KLB Secondary Physics Form 3, Pages 144-147

Current Electricity (II)

Resistors in Parallel - Theory and Calculations

By the end of the lesson, the learner should be able to:
Derive formula for resistors in parallel
-Calculate total resistance for parallel combination
-Understand current and voltage in parallel circuits
-Solve problems involving parallel resistors
-Apply parallel resistance in circuit analysis

Review series resistance through Q/A
-Derivation of 1/Rp = 1/R₁ + 1/R₂ + 1/R₃...
-Demonstration: measuring total resistance of parallel combination
-Analysis of voltage (same) and current (divided) in parallel
-Worked examples on parallel resistance calculations
-Problem-solving session

Resistors of known values
-Multimeter
-Connecting wires
-Circuit boards
-Calculator
-Parallel circuit diagrams
-Problem worksheets

KLB Secondary Physics Form 3, Pages 147-150

Current Electricity (II)

Mixed Circuits - Series-Parallel Combinations
Electromotive Force (EMF) and Terminal Voltage

By the end of the lesson, the learner should be able to:
Analyze circuits with series-parallel combinations
-Apply reduction techniques to complex circuits
-Calculate total resistance of mixed circuits
-Determine current and voltage in different branches
-Solve complex circuit problems

Q/A on parallel resistance
-Introduction to mixed circuit analysis techniques
-Step-by-step reduction of complex circuits
-Worked examples on series-parallel combinations
-Problem-solving on mixed circuits
-Discussion on circuit analysis strategies

Various resistors
-Circuit boards
-Connecting wires
-Multimeter
-Calculator
-Complex circuit diagrams
-Step-by-step analysis charts
High resistance voltmeter
-Various cells
-Switches
-Resistors
-EMF measurement setup
-Energy conversion charts

KLB Secondary Physics Form 3, Pages 150-153

Current Electricity (II)

Internal Resistance of Cells

By the end of the lesson, the learner should be able to:
Define internal resistance
-Understand the relationship E = V + Ir
-Calculate internal resistance experimentally
-Understand factors affecting internal resistance
-Apply internal resistance in circuit calculations

Q/A on EMF concepts
-Introduction to internal resistance concept
-Derivation of E = V + Ir relationship
-Experiment: measuring internal resistance using different loads
-Plotting E vs R graph to find internal resistance
-Discussion on factors affecting internal resistance

Various cells
-Resistors of different values
-Voltmeter
-Ammeter
-Connecting wires
-Graph paper
-Calculator
-Internal resistance apparatus

KLB Secondary Physics Form 3, Pages 150-153

Current Electricity (II)

Cells in Series and Parallel
Advanced Circuit Analysis and Problem Solving

By the end of the lesson, the learner should be able to:
Analyze cells connected in series
-Analyze cells connected in parallel
-Calculate total EMF and internal resistance
-Understand advantages of different connections
-Solve problems involving cell combinations
Apply Kirchhoff's laws to complex circuits
-Solve circuits with multiple sources
-Analyze circuits with internal resistance
-Use systematic approaches to circuit problems
-Integrate all electricity concepts

Review internal resistance through Q/A
-Analysis of identical cells in series connection
-Analysis of identical cells in parallel connection
-Calculation of equivalent EMF and internal resistance
-Discussion on practical applications and advantages
-Problem-solving on cell combinations
Q/A on cell combinations
-Application of Kirchhoff's current and voltage laws
-Systematic approach to complex circuit analysis
-Worked examples with multiple EMF sources
-Problem-solving session covering all electricity topics
-Discussion on practical circuit applications

Multiple identical cells
-Connecting wires
-Voltmeter
-Ammeter
-Resistors
-Calculator
-Cell combination diagrams
-Problem worksheets
Complex circuit examples
-Calculator
-Circuit analysis worksheets
-Multiple EMF sources
-Various resistors
-Comprehensive problem sets
-Kirchhoff's law charts

KLB Secondary Physics Form 3, Pages 152-153
KLB Secondary Physics Form 3, Pages 126-153

Heating Effect of Electric Current

Introduction to heating effect
Factors affecting heat produced - current and time
Factors affecting heat produced - resistance

By the end of the lesson, the learner should be able to:
Define heating effect of electric current
- Explain mechanism of heat production in conductors
- Investigate effect of current on resistance wire
- Observe temperature changes in conductors

Q/A on electric current from previous units
- Experiment investigating effect of current on coil temperature
- Observation of heating in different parts of circuit
- Discussion on electron collision mechanism

Battery, Resistance wire coils, Ammeter, Variable resistor, Thermometer, Stopwatch, Connecting wires
Resistance coils, Variable resistor, Ammeter, Thermometer, Stopwatch, Graph paper, Different current values
Coils of different resistance, Ammeter, Thermometer, Measuring instruments, Stopwatch, Calculation worksheets

KLB Secondary Physics Form 3, Pages 195-197

Heating Effect of Electric Current

Joule's law and electrical energy
Electrical power and energy calculations

By the end of the lesson, the learner should be able to:
State Joule's law of heating
- Derive H = I²Rt = VIt = V²t/R
- Calculate electrical energy and power
- Solve numerical problems on heating calculations

Discussion on Joule's heating law
- Mathematical derivations of heating formulas
- Problem solving on energy calculations
- Practical applications of heating law

Formula charts, Calculators, Problem worksheets, Electrical devices for analysis
Calculators, Unit conversion charts, Household appliance ratings, Electricity bills, Problem sets

KLB Secondary Physics Form 3, Pages 200-201

Heating Effect of Electric Current

Applications - electrical lighting and heating devices
Electrical safety - fuses and circuit protection
Efficiency calculations and motor problems
Series and parallel heating circuits

By the end of the lesson, the learner should be able to:
Describe working of filament lamp
- Explain choice of tungsten for filaments
- Describe working of electric iron, kettle and heaters
- Compare energy saving bulbs

Discussion on filament lamp construction
- Analysis of heating device designs
- Examination of actual heating appliances
- Efficiency comparisons

Filament lamps, Electric iron, Electric kettle, Heating elements, Energy saving bulbs, Appliance diagrams
Various fuses, Fuse holders, Circuit diagrams, Safety equipment demonstrations, Rating calculations
Motor specifications, Efficiency calculation worksheets, Power meters, Mechanical loading systems
Resistors in circuits, Ammeters, Voltmeters, Power calculation sheets, Circuit boards

KLB Secondary Physics Form 3, Pages 202-203