Thin Lenses

Types of Lenses and Effects on Light

By the end of the lesson, the learner should be able to:
Define a lens and distinguish between convex and concave lenses; Describe the effect of lenses on parallel rays of light; Explain convergence and divergence of light rays; Identify practical examples of different lens types

Q/A on refraction concepts; Experiment 1.1 - investigating effects of lenses on parallel rays using sunlight and ray box; Demonstration of convergence and divergence; Group identification of lens types in everyday objects; Drawing and analysis of ray diagrams

Ray box; Various convex and concave lenses; White screen; Plane mirror; Card with parallel slits; Sunlight or strong lamp

KLB Secondary Physics Form 4, Pages 1-6

Thin Lenses

Definition of Terms and Ray Diagrams
Image Formation by Converging Lenses

By the end of the lesson, the learner should be able to:
Define centre of curvature, principal axis, optical centre, principal focus and focal length; Distinguish between real and virtual focus; State and apply the three important rays for lens diagrams; Construct basic ray diagrams for lenses

Q/A review of lens effects; Guided discovery of lens terminology using practical demonstrations; Step-by-step construction of ray diagrams using the three important rays; Practice drawing ray paths for parallel rays, rays through focus, and rays through optical centre; Group work on ray diagram construction

Various lenses; Rulers; Graph paper; Ray boxes; Charts showing lens terminology; Drawing materials; Laser pointers (if available)
Converging lenses; Objects; White screen; Metre rule; Candle; Graph paper; Charts showing applications; Camera (if available)

KLB Secondary Physics Form 4, Pages 3-8

Thin Lenses

Image Formation by Diverging Lenses and Linear Magnification
The Lens Formula

By the end of the lesson, the learner should be able to:
Construct ray diagrams for diverging lenses; Explain why diverging lenses always form virtual, erect, diminished images; Define linear magnification and derive its formula; Calculate magnification using height and distance ratios; Solve Examples 1, 2, and 3 from textbook

Q/A on converging lens images; Ray diagram construction for diverging lenses; Mathematical derivation of magnification formulae; Step-by-step solution of textbook examples; Scale drawing practice; Group problem-solving on magnification calculations

Diverging lenses; Graph paper; Rulers; Calculators; Examples from textbook; Objects of known heights; Measuring equipment
Mathematical instruments; Charts showing derivation; Calculators; Worked examples; Sign convention chart; Practice worksheets

KLB Secondary Physics Form 4, Pages 11-14

Thin Lenses

Determination of Focal Length I
Determination of Focal Length II

By the end of the lesson, the learner should be able to:
Estimate focal length using distant objects (Experiment 1.2); Determine focal length using plane mirror method (Experiment 1.3); Explain the principle behind each method; Measure focal length accurately and identify sources of error

Q/A on focal length concept; Practical performance of Experiment 1.2 - distant object method; Demonstration and practice of Experiment 1.3 - plane mirror method (both no-parallax and illuminated object methods); Recording and analysis of results; Discussion of accuracy and error sources

Converging lenses; Lens holders; Metre rule; White screen; Distant objects; Plane mirror; Pins; Cork; Glass rod; Light source; Cardboard with cross-wires
Experimental setup materials; Graph paper; Calculators; Data tables; Examples 8-10 from textbook; Materials for displacement method

KLB Secondary Physics Form 4, Pages 16-19

Thin Lenses

Power of Lens and Simple Microscope
Compound Microscope

By the end of the lesson, the learner should be able to:
Define power of a lens and calculate using P = 1/f; Use dioptre as unit and distinguish positive/negative power; Explain working of simple microscope (magnifying glass); Understand why short focal length lenses are preferred; Calculate magnification of simple microscope

Q/A on focal length concepts; Introduction to lens power with practical examples; Power calculations and comparisons; Demonstration of simple microscope setup; Analysis of magnification factors; Discussion of applications and limitations of magnifying glass

Various lenses of different focal lengths; Magnifying glasses; Small objects; Calculators; Power calculation charts; Small print materials; Biological specimens
Compound microscope; Charts showing microscope structure; Lenses representing objective and eyepiece; Calculators; Example 11 from textbook; Ray tracing materials

KLB Secondary Physics Form 4, Pages 26-28

Thin Lenses

The Human Eye

By the end of the lesson, the learner should be able to:
Describe structure of human eye and functions of each part; Explain accommodation process and role of ciliary muscles; Define near point and far point; Understand how eye focuses at different distances; Compare eye structure with camera

Introduction to human eye as natural optical instrument; Detailed study of eye structure using charts/models; Demonstration of accommodation using flexible lens model; Practical measurement of near and far points; Comparison table of eye vs camera similarities and differences

Charts/models of human eye; Torch for demonstrations; Eye model with flexible lens; Objects at various distances; Measuring equipment; Camera comparison charts

KLB Secondary Physics Form 4, Pages 30-32

Thin Lenses

Defects of Vision

By the end of the lesson, the learner should be able to:
Describe short sight (myopia) and its causes; Explain correction of myopia using diverging lenses; Describe long sight (hypermetropia) and its causes; Explain correction of hypermetropia using converging lenses; Draw ray diagrams showing defects and their corrections

Q/A on normal vision and accommodation; Analysis of myopia - causes, effects, and correction; Ray diagrams for uncorrected and corrected myopia; Study of hypermetropia - causes, effects, and correction; Ray diagrams for uncorrected and corrected hypermetropia; Demonstration using appropriate lenses

Charts showing vision defects; Converging and diverging lenses; Eye models; Spectacles with different lenses; Vision test materials; Ray diagram materials

KLB Secondary Physics Form 4, Pages 32-33

Thin Lenses

The Camera and Applications Review

By the end of the lesson, the learner should be able to:
Describe camera structure and working principles; Explain functions of camera lens, shutter, aperture, and film; Compare camera with human eye highlighting similarities and differences; Review all applications of lenses in optical instruments

Review of optical instruments studied; Analysis of camera components and their functions; Detailed comparison of camera and eye; Discussion of focusing mechanisms; Comprehensive review of lens applications in telescope, microscope, camera, spectacles, and magnifying glass

Camera (if available); Charts showing camera structure; Comparison tables; Review charts of all applications; Summary materials; Demonstration equipment

KLB Secondary Physics Form 4, Pages 33-35

Uniform Circular Motion

Introduction and Angular Displacement

By the end of the lesson, the learner should be able to:
Define uniform circular motion and give examples; Define angular displacement and its unit (radian); Convert between degrees and radians; Derive the relationship s = rθ; Solve Example 1 from textbook

Q/A on linear motion concepts; Introduction to circular motion using real-life examples (merry-go-round, wheels, planets); Definition and demonstration of angular displacement; Mathematical relationship between arc length, radius and angle; Practical measurement of angles in radians; Solution of Example 1

Merry-go-round model or pictures; String and objects for circular motion; Protractors; Calculators; Charts showing degree-radian conversion; Measuring wheels

KLB Secondary Physics Form 4, Pages 37-39

Uniform Circular Motion

Angular Velocity and Linear Velocity

By the end of the lesson, the learner should be able to:
Define angular velocity (ω) and its units; Derive the relationship v = rω; Calculate period (T) and frequency (f) of circular motion; Solve Examples 2(a) and 2(b) from textbook; Relate linear and angular quantities

Review of angular displacement through Q/A; Introduction to angular velocity concept; Mathematical derivation of v = rω relationship; Exploration of period and frequency relationships; Step-by-step solution of Examples 2(a) and 2(b); Practical demonstration using rotating objects; Group calculations involving different circular motions

Stopwatch; Rotating objects (turntables, wheels); String and masses; Calculators; Formula charts; Examples from textbook; Measuring equipment

KLB Secondary Physics Form 4, Pages 38-40

Uniform Circular Motion

Centripetal Acceleration
Centripetal Force and Factors Affecting It

By the end of the lesson, the learner should be able to:
Explain why circular motion involves acceleration despite constant speed; Derive centripetal acceleration formula a = v²/r = rω²; Understand direction of centripetal acceleration; Solve Example 3 from textbook; Apply acceleration concepts to circular motion problems

Q/A review of velocity and acceleration concepts; Explanation of acceleration in circular motion using vector analysis; Mathematical derivation of centripetal acceleration; Discussion of acceleration direction (toward center); Step-by-step solution of Example 3; Practical demonstration of centripetal acceleration effects

Vector diagrams; Rotating objects; Calculators; Charts showing acceleration derivation; Example 3 materials; Demonstration of circular motion with varying speeds
Metal pegs; Turntable and motor; Variable resistor; Dry cell; Metal ball and string; Spring balance; Clock; Graph paper; Calculators

KLB Secondary Physics Form 4, Pages 40-42

Uniform Circular Motion

Experimental Investigation of Centripetal Force

By the end of the lesson, the learner should be able to:
Perform Experiment 2.2 investigating speed vs radius relationship; Plot graphs of F vs ω² and v² vs r; Analyze experimental results and draw conclusions; Understand the relationship F ∝ mv²/r; Apply experimental findings to solve problems

Q/A on previous experiment results; Setup and performance of Experiment 2.2 - variation of speed with radius; Data collection for different radii; Graph plotting and analysis; Verification of theoretical relationships; Group analysis of experimental errors and improvements; Application of results to problem solving

Same apparatus as Experiment 2.1; Graph paper; Additional measuring equipment; Data recording tables; Calculators; Analysis worksheets

KLB Secondary Physics Form 4, Pages 44-47

Uniform Circular Motion

Case Examples - Cars and Banking

By the end of the lesson, the learner should be able to:
Explain circular motion of cars on level roads; Understand role of friction in providing centripetal force; Describe banking of roads and its advantages; Derive critical speed for banked tracks; Explain aircraft banking principles

Review of centripetal force concepts; Analysis of car motion on circular bends; Discussion of friction as centripetal force; Introduction to banked roads and critical speed; Mathematical analysis of banking angles; Explanation of aircraft banking mechanisms; Problem-solving involving banking situations

Model cars and tracks; Inclined plane demonstrations; Charts showing banking principles; Calculators; Friction demonstration materials; Pictures of banked roads and aircraft

KLB Secondary Physics Form 4, Pages 47-50

Uniform Circular Motion

Case Examples - Cyclists and Conical Pendulum

By the end of the lesson, the learner should be able to:
Analyze forces on cyclists moving in circular tracks; Explain cyclist leaning and conditions for no skidding; Describe conical pendulum motion; Derive equations for conical pendulum; Solve Example 5 from textbook

Q/A on banking concepts; Analysis of cyclist motion on circular tracks; Force analysis and conditions for stability; Introduction to conical pendulum; Mathematical analysis of pendulum motion; Step-by-step solution of Example 5; Practical demonstration of conical pendulum

Model cyclists; Pendulum apparatus; String and masses; Force diagrams; Calculators; Example 5 materials; Protractors for angle measurement

KLB Secondary Physics Form 4, Pages 50-52

Uniform Circular Motion

Motion in Vertical Circle

By the end of the lesson, the learner should be able to:
Analyze forces in vertical circular motion; Understand variation of tension at different positions; Derive expressions for tension at top and bottom positions; Calculate minimum speed for vertical circular motion; Apply concepts to practical examples (bucket of water, loop-the-loop)

Review of circular motion in horizontal plane; Introduction to vertical circular motion; Force analysis at different positions in vertical circle; Mathematical derivation of tension variations; Discussion of minimum speed requirements; Practical examples and safety considerations; Problem-solving involving vertical motion

String and masses for vertical motion; Bucket and water (demonstration); Model loop-the-loop track; Force analysis charts; Safety equipment; Calculators

KLB Secondary Physics Form 4, Pages 52-54

Uniform Circular Motion

Applications - Centrifuges and Satellites

By the end of the lesson, the learner should be able to:
Explain working principles of centrifuges; Describe separation of particles using centripetal force; Understand satellite motion and gravitational force; Apply Newton's law of gravitation to satellite orbits; Explain parking orbits and their applications

Q/A on centripetal force applications; Detailed study of centrifuge operation; Analysis of particle separation mechanisms; Introduction to satellite motion; Application of universal gravitation law; Discussion of geostationary satellites; Analysis of satellite velocities and orbital periods

Centrifuge model or pictures; Separation demonstration materials; Satellite orbit charts; Calculators; Newton's gravitation materials; Model solar system

KLB Secondary Physics Form 4, Pages 54-55

Floating and Sinking

Introduction and Cause of Upthrust

By the end of the lesson, the learner should be able to:
Explain why objects feel lighter in fluids; Define upthrust and identify its effects; Perform Experiment 3.1 investigating upthrust and weight of fluid displaced; Derive mathematical expression for upthrust using pressure concepts; Verify Archimedes' principle experimentally

Q/A on pressure in liquids; Introduction using steel ferry floating on water; Performance of Experiment 3.1 - relationship between upthrust and weight of displaced fluid; Mathematical derivation of upthrust U = ρVg; Analysis of experimental results; Discussion of pressure differences causing upthrust

Spring balance; Objects (stones); String; Eureka can; Beaker; Water; Measuring cylinder; Beam balance; Dense objects; Charts showing pressure variation

KLB Secondary Physics Form 4, Pages 58-63

Floating and Sinking

Upthrust in Gases and Archimedes' Principle

By the end of the lesson, the learner should be able to:
Explain upthrust in gases with examples; State Archimedes' principle clearly; Apply Archimedes' principle to solve problems; Solve Examples 1, 2, and 3 from textbook; Calculate apparent weight and upthrust in different fluids

Review of upthrust in liquids through Q/A; Discussion of upthrust in gases using balloon examples; Statement and explanation of Archimedes' principle; Step-by-step solution of Examples 1-3; Problem-solving involving apparent weight calculations; Group work on upthrust calculations

Balloons; Helium or hydrogen (if available); Objects of known density; Calculators; Examples from textbook; Different liquids for demonstration; Measuring equipment

KLB Secondary Physics Form 4, Pages 60-66

Floating and Sinking

Law of Flotation and Applications

By the end of the lesson, the learner should be able to:
Perform Experiment 3.2 investigating upthrust on floating objects; State the law of flotation; Explain the relationship between weight of object and weight of displaced fluid; Solve Examples 4, 5, 6, and 7 involving floating objects; Apply law of flotation to balloons and ships

Q/A on Archimedes' principle; Performance of Experiment 3.2 - investigating floating objects; Analysis of experimental observations; Statement of law of flotation; Step-by-step solution of Examples 4-7; Discussion of applications in balloons, ships, and everyday objects

Test tubes; Sand; Measuring cylinder; Water; Balance; Floating objects; Examples from textbook; Calculators; Model boats; Balloon demonstrations

KLB Secondary Physics Form 4, Pages 64-69

Floating and Sinking

Relative Density Determination

By the end of the lesson, the learner should be able to:
Define relative density of solids and liquids; Use Archimedes' principle to determine relative density; Apply the formula: RD = Weight in air/(Weight in air - Weight in fluid); Solve Examples 8, 9, 10, 11, and 12 from textbook; Calculate relative density using different methods

Review of density concepts through Q/A; Introduction to relative density using practical examples; Mathematical derivation of relative density formulae; Step-by-step solution of Examples 8-12; Practical determination of relative density for various materials; Group calculations and comparisons

Spring balance; Various solid objects; Different liquids; Measuring cylinders; Calculators; Examples from textbook; Objects of unknown density; Data recording sheets

KLB Secondary Physics Form 4, Pages 69-74

Floating and Sinking

Archimedes' Principle and Moments
Applications - Hydrometer and Practical Instruments

By the end of the lesson, the learner should be able to:
Perform Experiment 3.3 determining relative density using moments; Understand the principle of moments in relative density determination; Plot graphs of d₁ against d₂ and determine slopes; Apply moments method to determine relative density of liquids; Explain advantages of moments method over direct weighing

Q/A on relative density calculations; Setup and performance of Experiment 3.3 - relative density using moments; Data collection and graph plotting; Analysis of graph slopes and their significance; Application to liquids determination; Discussion of method advantages and accuracy

Metre rule; Clamps and stands; Solid objects; Metal blocks; Water and other liquids; Graph paper; Calculators; Data recording tables; Balance setup materials
Hydrometer (if available); Different density liquids; Measuring cylinders; Calculators; Examples from textbook; Charts showing hydrometer types; Battery acid hydrometer demonstration

KLB Secondary Physics Form 4, Pages 71-74

Floating and Sinking

Applications - Ships, Submarines, and Balloons

By the end of the lesson, the learner should be able to:
Explain how steel ships float on water; Describe working principle of submarines; Understand how balloons achieve lift and control altitude; Analyze the role of displaced fluid in each application; Apply principles to solve practical problems involving floating vessels

Q/A on hydrometer applications; Analysis of ship design and floating principles; Detailed study of submarine operation and ballast tanks; Exploration of balloon physics and gas density effects; Discussion of load limits and stability; Problem-solving involving practical floating applications

Model ships and submarines; Balloon demonstrations; Charts showing ship cross-sections; Submarine ballast tank models; Different density materials; Calculators; Application examples

KLB Secondary Physics Form 4, Pages 77

Electromagnetic Spectrum

Introduction and Properties of Electromagnetic Waves

By the end of the lesson, the learner should be able to:
Define electromagnetic waves and identify their nature; State properties common to all electromagnetic waves; Arrange electromagnetic radiations in order of wavelength and frequency; Calculate wave properties using c = fλ; Solve Examples 1 and 2 from textbook

Q/A on wave concepts from previous studies; Introduction to electromagnetic waves using everyday examples; Study of electromagnetic spectrum chart; Discussion of wave properties (speed, frequency, wavelength); Mathematical relationship between wave parameters; Solution of Examples 1 and 2 involving calculations

Electromagnetic spectrum charts; Wave demonstration materials; Calculators; Radio; Mobile phone; Examples from textbook; Charts showing wave properties

KLB Secondary Physics Form 4, Pages 79-81

Electromagnetic Spectrum

Production and Detection of Electromagnetic Waves I

By the end of the lesson, the learner should be able to:
Explain production of gamma rays, X-rays, and ultraviolet radiation; Describe detection methods for high-energy radiations; Understand energy transitions in atoms and nuclei; Relate wave energy to frequency using E = hf; Solve Example 3 involving X-ray calculations

Review of electromagnetic properties through Q/A; Study of high-energy radiation production mechanisms; Analysis of detection methods (photographic plates, G-M tubes, fluorescent materials); Discussion of atomic and nuclear energy changes; Step-by-step solution of Example 3; Safety considerations for high-energy radiations

Charts showing radiation production; Photographic film; Fluorescent materials; UV lamp (if available); Geiger counter (if available); Example 3 materials; Safety equipment demonstrations

KLB Secondary Physics Form 4, Pages 81-82

Electromagnetic Spectrum

Production and Detection of Electromagnetic Waves II

By the end of the lesson, the learner should be able to:
Explain production of visible light, infrared, microwaves, and radio waves; Describe detection methods for each radiation type; Understand role of oscillating circuits in radio wave production; Compare detection mechanisms across the spectrum; Demonstrate detection of some radiations

Q/A on high-energy radiations; Study of lower-energy radiation production (thermal, electronic oscillations); Analysis of detection methods (eyes, thermopiles, crystal detectors, radio receivers); Practical demonstrations of infrared detection; Discussion of antenna and oscillating circuit principles; Group identification of sources and detectors

Infrared sources (heaters); Thermometer with blackened bulb; Radio receivers; Microwave oven (demonstration); Oscillating circuit models; Various electromagnetic sources

KLB Secondary Physics Form 4, Pages 81-82

Electromagnetic Spectrum

Applications of Electromagnetic Waves I

By the end of the lesson, the learner should be able to:
Describe medical applications of gamma rays and X-rays; Explain industrial uses of high-energy radiations; Understand applications in sterilization and cancer therapy; Discuss X-ray photography and crystallography; Analyze benefits and limitations of high-energy radiation applications

Review of radiation properties and production; Detailed study of gamma ray applications (sterilization, cancer treatment, flaw detection); Analysis of X-ray applications (medical photography, security, crystallography); Discussion of controlled radiation exposure; Examination of X-ray photographs and medical applications

X-ray photographs; Medical imaging examples; Industrial radiography charts; Cancer treatment information; Sterilization process diagrams; Safety protocol charts

KLB Secondary Physics Form 4, Pages 82-84

Electromagnetic Spectrum

Applications of Electromagnetic Waves II

By the end of the lesson, the learner should be able to:
Explain applications of ultraviolet radiation; Describe uses of visible light in technology; Understand infrared applications in heating and imaging; Analyze microwave applications in cooking and radar; Discuss radio wave applications in communication

Q/A on high-energy radiation applications; Study of UV applications (fluorescence, sterilization, vitamin D, forgery detection); Analysis of visible light uses (photography, optical fibers, lasers); Exploration of infrared applications (heating, night vision, remote controls); Discussion of microwave and radio wave technologies

UV lamp demonstrations; Optical fiber samples; Infrared thermometer; Microwave oven (demonstration); Radio equipment; Remote controls; Radar images; Communication devices

KLB Secondary Physics Form 4, Pages 82-85

Electromagnetic Spectrum

Specific Applications - Radar and Microwave Cooking

By the end of the lesson, the learner should be able to:
Explain principles of radar (radio detection and ranging); Describe microwave oven operation and safety features; Understand reflection and detection in radar systems; Explain how microwaves heat food molecules; Apply wave principles to practical technologies

Review of microwave and radio wave properties; Detailed analysis of radar operation and applications; Study of microwave oven components (magnetron, stirrer, safety features); Discussion of wave reflection and detection principles; Analysis of molecular heating mechanisms; Safety considerations and precautions

Radar system diagrams; Microwave oven cross-section charts; Wave reflection demonstrations; Safety instruction materials; Magnetron information; Aircraft/ship tracking examples

KLB Secondary Physics Form 4, Pages 84-85

Electromagnetic Spectrum

Hazards and Safety Considerations

By the end of the lesson, the learner should be able to:
Identify hazards of high-energy electromagnetic radiations; Explain biological effects of UV, X-rays, and gamma rays; Describe safety measures for radiation protection; Understand delayed effects like cancer and genetic damage; Apply safety principles in radiation use

Q/A on electromagnetic applications; Study of radiation hazards and biological effects; Analysis of skin damage, cell destruction, and genetic effects; Discussion of Chernobyl disaster and radiation accidents; Exploration of safety measures (shielding, distance, time limits); Application of ALARA principle (As Low As Reasonably Achievable)

Radiation hazard charts; Safety equipment demonstrations; Chernobyl disaster information; Biological effect diagrams; Safety protocol materials; Radiation protection examples

KLB Secondary Physics Form 4, Pages 85

Electromagnetic Induction

Introduction and Historical Background

Conditions for Electromagnetic Induction - Straight Conductor

By the end of the lesson, the learner should be able to:
Define electromagnetic induction and its significance; Explain Faraday's discovery and its impact on modern technology; Understand the relationship between magnetism and electricity; Identify examples of electromagnetic induction in daily life; Appreciate the importance of relative motion in electromagnetic phenomena

Q/A on magnetic fields and electric current relationships from previous studies; Introduction to Michael Faraday's discovery and its historical significance; Discussion of electromagnetic induction examples in daily life (generators, transformers, motors); Overview of chapter content and learning objectives; Introduction to practical applications in power generation and electronics

Charts showing Faraday's experiments; Pictures of power stations; Transformers; Generators; Historical timeline of electromagnetic discoveries; Real-world applications display
Thick electric conductor; U-shaped magnet; Galvanometer; Connecting wires; Clamp and stand setup; Data recording sheets

KLB Secondary Physics Form 4, Pages 86

Electromagnetic Induction

Conditions for Electromagnetic Induction - Coils

By the end of the lesson, the learner should be able to:
Perform Experiment 5.1 using coils; Compare induction effects in straight conductors vs coils; Observe effects of magnet movement into and out of coils; Understand flux linkage concept; Analyze why coils are more effective than single conductors

Continuation of Experiment 5.1 using coil instead of straight conductor; Investigation of magnet movement into coil, out of coil, and stationary positions; Comparison of deflection magnitudes between straight conductor and coil setups; Analysis of why coils produce larger induced e.m.f.; Discussion of magnetic flux and flux linkage concepts

Coils of different sizes; Magnets of various strengths; Galvanometer; Connecting wires; Comparison data sheets

KLB Secondary Physics Form 4, Pages 87-88

Electromagnetic Induction

Factors Affecting Induced E.M.F. - Rate of Change

By the end of the lesson, the learner should be able to:
Perform Experiment 5.2 investigating rate of change effects; Understand relationship between speed of motion and induced e.m.f.; Collect and analyze data on rate of flux change; Establish that faster changes produce larger e.m.f.; Apply findings to practical situations

Performance of Experiment 5.2 investigating relationship between rate of change of magnetic flux and induced e.m.f.; Systematic variation of magnet withdrawal speeds (very fast, moderate, very slow); Recording and comparison of galvanometer deflections; Data analysis and conclusion drawing; Discussion of practical implications in generators and other applications

Coil of at least 50 turns; Sensitive galvanometer; Magnet; Stopwatch; Data collection tables; Graph paper for analysis

KLB Secondary Physics Form 4, Pages 88-89

Electromagnetic Induction

Factors Affecting Induced E.M.F. - Magnetic Field Strength

By the end of the lesson, the learner should be able to:
Perform Experiment 5.3 investigating magnetic field strength effects; Understand relationship between field strength and induced e.m.f.; Control variables in electromagnetic experiments; Use electromagnets to vary field strength; Apply experimental findings to solve problems

Performance of Experiment 5.3 investigating relationship between magnetic field strength and induced e.m.f.; Setup of electromagnet with variable current control; Investigation of wire PQ movement in different field strengths; Recording galvanometer deflections for different electromagnet currents; Analysis of results and relationship establishment

U-shaped electromagnet; Variable resistor; Wire PQ; Galvanometer; Ammeter; Connecting wires; Power supply; Data recording materials

KLB Secondary Physics Form 4, Pages 89

Electromagnetic Induction

Factors Affecting Induced E.M.F. - Number of Turns

By the end of the lesson, the learner should be able to:
Perform Experiment 5.4 investigating effect of coil turns; Understand relationship between number of turns and induced e.m.f.; Construct coils with different numbers of turns; Analyze why more turns produce larger e.m.f.; State Faraday's law of electromagnetic induction

Performance of Experiment 5.4 investigating relationship between number of turns and induced e.m.f.; Construction of solenoids with 60, 50, 40, 30, and 20 turns; Systematic testing with same magnet withdrawal speed; Recording and analysis of galvanometer readings; Mathematical relationship establishment; Statement of Faraday's law based on experimental evidence

Insulated copper wire; Sensitive galvanometer; Magnet; Connecting wires; Wire cutting and measuring tools; Data analysis sheets

KLB Secondary Physics Form 4, Pages 89-90

Electromagnetic Induction

Lenz's Law and Direction of Induced Current

By the end of the lesson, the learner should be able to:
Perform Experiment 5.5 determining direction of induced current; State Lenz's law and explain its significance; Understand energy conservation in electromagnetic induction; Predict current direction using Lenz's law; Relate Lenz's law to conservation of energy principle

Performance of Experiment 5.5(a) establishing galvanometer deflection direction; Performance of Experiment 5.5(b) investigating induced current direction with magnet movement; Analysis of current directions and magnetic pole formation; Statement and explanation of Lenz's law; Discussion of energy conservation and opposition principle; Practice in predicting current directions

Variable resistor; Sensitive center-zero galvanometer; Connecting wires; Coil; Magnet; Switch; Battery; Direction analysis charts

KLB Secondary Physics Form 4, Pages 90-93

Electromagnetic Induction

Fleming's Right-Hand Rule

By the end of the lesson, the learner should be able to:
Perform Experiment 5.6 with straight conductors; State Fleming's right-hand rule (dynamo rule); Apply the rule to determine direction of induced current; Understand relationship between motion, field, and current directions; Solve Example 1 involving square loop movement

Performance of Experiment 5.6 determining induced current direction in straight conductor; Introduction and demonstration of Fleming's right-hand rule; Practice applying the rule to various conductor movements; Step-by-step solution of Example 1 (square loop in magnetic field); Analysis of current directions in different parts of the loop; Verification of Fleming's rule consistency with Lenz's law

U-shaped magnet; Thick wire AB; Marked center-zero galvanometer; Hand models for rule demonstration; Example 1 setup materials; Direction analysis worksheets

KLB Secondary Physics Form 4, Pages 93-97

Electromagnetic Induction

Applications of Induction Laws

By the end of the lesson, the learner should be able to:
Solve Examples 2 and 3 involving current direction; Apply Lenz's law to predict current directions in circuits; Understand induced current effects in neighboring circuits; Analyze changing magnetic fields and their effects; Use both Fleming's rule and Lenz's law in problem solving

Q/A review of Fleming's rule and Lenz's law; Step-by-step solution of Example 2 (current in conductor AB affecting nearby loop); Detailed analysis of Example 3 (magnet movement and coil current direction); Practice problems involving current direction prediction; Group work on applying both laws to various scenarios; Discussion of consistency between different methods

Examples 2 and 3 setup materials; Problem-solving worksheets; Charts showing current direction analysis; Group work materials; Calculators

KLB Secondary Physics Form 4, Pages 94-97

Electromagnetic Induction

Mutual Induction

By the end of the lesson, the learner should be able to:
Define mutual induction and demonstrate its occurrence; Perform Experiment 5.7 showing mutual induction between coils; Explain factors affecting mutual induction; Understand primary and secondary coil relationships; Discuss enhancement methods using iron cores

Q/A on electromagnetic induction principles; Introduction to mutual induction concept and definition; Performance of Experiment 5.7 demonstrating mutual induction between primary and secondary coils; Investigation of switching effects, current changes, and A.C. source effects; Analysis of mutual induction enhancement using soft iron rod and ring; Discussion of applications in transformers

Two coils P and S; Galvanometer; Battery; A.C. power source; Switch; Rheostat; Connecting wires; Soft iron rod; Soft iron ring; Enhancement demonstration materials

KLB Secondary Physics Form 4, Pages 97-100

Electromagnetic Induction

Transformers - Basic Principles

By the end of the lesson, the learner should be able to:
Describe transformer structure and components; Explain working principle based on mutual induction; Perform Experiment 5.10 investigating secondary e.m.f. variation; Understand primary and secondary coil functions; Distinguish between step-up and step-down transformers

Review of mutual induction through Q/A; Introduction to transformer structure (primary coil, secondary coil, iron core); Performance of Experiment 5.10 - variation of secondary e.m.f. with number of turns; Observation of bulb brightness changes with turn variations; Analysis of step-up vs step-down transformer characteristics; Introduction to transformer symbols and representations

Long insulated copper wire; Soft iron rod; Low frequency A.C. source; A.C. voltmeter; Switch; Bulb; Transformer construction materials; Symbol charts

KLB Secondary Physics Form 4, Pages 100-102

Electromagnetic Induction

Transformer Equations and Calculations
Transformer Energy Losses and Example 6

By the end of the lesson, the learner should be able to:
Derive transformer turns rule equation; Apply transformer equations for voltage and current relationships; Calculate transformer efficiency; Solve Examples 4 and 5 involving transformer problems; Understand ideal vs practical transformer differences

Q/A on transformer working principles; Mathematical derivation of turns rule (Vp/Vs = Np/Ns); Development of current relationship (IpVp = IsVs for ideal transformer); Introduction to efficiency calculations; Step-by-step solution of Examples 4 and 5; Discussion of ideal transformer assumptions vs practical limitations

Calculators; Examples 4 and 5 materials; Mathematical derivation charts; Efficiency calculation worksheets; Transformer specification data
Charts showing energy losses; Laminated core samples; Example 6 complex setup; Power transmission diagrams; Efficiency calculation materials; Loss minimization demonstration aids

KLB Secondary Physics Form 4, Pages 102-105

Electromagnetic Induction

Applications - Generators, Microphones, and Induction Coils

By the end of the lesson, the learner should be able to:
Explain structure and working of A.C. and D.C. generators; Describe moving-coil microphone operation; Understand induction coil structure and applications; Compare slip rings with split ring commutators; Analyze generator output waveforms and applications

Review of electromagnetic induction in rotating systems; Detailed study of A.C. generator structure and sinusoidal output; Analysis of D.C. generator with split ring commutator; Explanation of moving-coil microphone components and sound conversion; Description of induction coil operation and high voltage generation; Discussion of applications in car ignition systems

A.C. generator model; D.C. generator model; Moving-coil microphone demonstration; Induction coil setup; Output waveform charts; Slip ring and commutator comparisons; Bicycle dynamo

KLB Secondary Physics Form 4, Pages 108-112

Mains Electricity

Sources of Mains Electricity
The Grid System and Power Transmission

By the end of the lesson, the learner should be able to:

State the main sources of mains electricity
Explain how different sources generate electrical energy
Compare advantages and disadvantages of different power sources
Describe the environmental impact of various power sources

Prior knowledge review on electrical energy
Discussion on local power sources in Kenya
Field trip planning to nearby power station
Group presentations on different power sources
Q&A session on power generation methods

Pictures of power stations
Charts showing different energy sources
Videos of power generation
Maps of Kenya's power grid
Sample coal, biomass materials
Chart of national grid system
Transmission line models
Maps showing power lines
Transformer models
Voltage measurement devices

KLB Secondary Physics Form 4, Pages 117

Mains Electricity

High Voltage Transmission and Power Losses
Domestic Wiring System

By the end of the lesson, the learner should be able to:

Explain why power is transmitted at high voltage
Calculate power losses in transmission
State dangers of high voltage transmission
Apply the formula P = I²R to transmission problems

Review of Ohm's law and power formulas
Demonstration of power loss calculations
Worked examples on transmission efficiency
Discussion on safety measures for transmission lines
Group problem-solving activities

Calculators
Worked example sheets
Pictures of transmission towers
Safety warning signs
Formula charts
House wiring components
Fuse box model
Different types of fuses
Electrical cables (samples)
Circuit diagrams
Multimeter

KLB Secondary Physics Form 4, Pages 118-121

Mains Electricity

Fuses, Circuit Breakers and Safety Devices
Ring Mains Circuit and Three-Pin Plugs

By the end of the lesson, the learner should be able to:

Explain the function of fuses in electrical circuits
Compare fuses and circuit breakers
Select appropriate fuse ratings for different appliances
Describe safety measures in electrical installations

Review of domestic wiring components
Examination of different fuse types
Calculation of appropriate fuse ratings
Demonstration of circuit breaker operation
Discussion on electrical safety

Various fuses (2A, 5A, 13A)
Circuit breakers
Fuse wire samples
Electrical appliances
Calculators
Safety equipment samples
Three-pin plugs
Electrical cables
Wire strippers
Screwdrivers
Ring mains circuit model
Color-coded wires

KLB Secondary Physics Form 4, Pages 122-123

Mains Electricity

Electrical Energy Consumption and Costing
Problem Solving and Applications

By the end of the lesson, the learner should be able to:

Define kilowatt-hour (kWh)
Calculate electrical energy consumption
Determine cost of electrical energy
Apply energy formulas to practical problems

Review of power and energy concepts
Introduction to kilowatt-hour unit
Worked examples on energy calculations
Practice problems on electricity billing
Analysis of electricity bills

Calculators
Sample electricity bills
Electrical appliances with ratings
Stop watches
Energy meter model
Formula charts
Problem sheets
Past examination questions
Real electricity bills
Energy conservation charts

KLB Secondary Physics Form 4, Pages 125-128