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
Centripetal Acceleration

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
Vector diagrams; Rotating objects; Calculators; Charts showing acceleration derivation; Example 3 materials; Demonstration of circular motion with varying speeds

KLB Secondary Physics Form 4, Pages 38-40

Uniform Circular Motion

Centripetal Force and Factors Affecting It

By the end of the lesson, the learner should be able to:
Explain the need for centripetal force in circular motion; State factors affecting centripetal force (mass, speed, radius); Derive centripetal force formula F = mv²/r = mrω²; Perform Experiment 2.1 investigating F vs ω²; Solve Example 4 from textbook

Review of Newton's laws and centripetal acceleration; Introduction to centripetal force concept; Experimental investigation of factors affecting centripetal force; Performance of Experiment 2.1 - relationship between F and ω²; Data collection and analysis; Solution of Example 4; Discussion of practical implications

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 42-47

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
Relative Density Determination

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
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 64-69

Floating and Sinking

Archimedes' Principle and Moments

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

KLB Secondary Physics Form 4, Pages 71-74

Floating and Sinking

Applications - Hydrometer and Practical Instruments

By the end of the lesson, the learner should be able to:
Explain the working principle of hydrometers; Describe structure and features of practical hydrometers; Solve Examples 12 and 13 involving hydrometer calculations; Understand applications in measuring density of milk, battery acid, and beer; Calculate hydrometer dimensions and floating positions

Review of law of flotation through Q/A; Detailed study of hydrometer structure and operation; Analysis of hydrometer sensitivity and design features; Step-by-step solution of Examples 12-13; Discussion of specialized hydrometers (lactometer, battery acid hydrometer); Practical calculations involving hydrometer floating

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 74-77

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
Hazards and Safety Considerations

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

KLB Secondary Physics Form 4, Pages 84-85

Electromagnetic Induction

Introduction and Historical Background

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

KLB Secondary Physics Form 4, Pages 86

Electromagnetic Induction

Conditions for Electromagnetic Induction - Straight Conductor

By the end of the lesson, the learner should be able to:
Perform Experiment 5.1 using straight conductor; Identify conditions necessary for inducing e.m.f. in a straight conductor; Observe effects of different types of motion on induced current; Understand the importance of relative motion between conductor and magnetic field; Analyze galvanometer deflections

Performance of Experiment 5.1 using straight conductor AB in U-shaped magnet; Systematic investigation of conductor movement (vertical up/down, parallel to field, stationary, different angles); Observation and recording of galvanometer deflections; Analysis of current direction changes with motion reversal; Discussion of relative motion importance and field cutting concept

Thick electric conductor; U-shaped magnet; Galvanometer; Connecting wires; Clamp and stand setup; Data recording sheets

KLB Secondary Physics Form 4, Pages 86-87

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
Mutual Induction

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
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 94-97

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

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

KLB Secondary Physics Form 4, Pages 102-105

Electromagnetic Induction

Transformer Energy Losses and Example 6

By the end of the lesson, the learner should be able to:
Identify four main energy losses in transformers; Explain methods to minimize each type of energy loss; Understand lamination and its purpose; Solve Example 6 involving power transmission system; Calculate efficiency and power losses in practical systems

Review of ideal transformer equations; Analysis of energy losses (flux leakage, copper losses, eddy currents, hysteresis loss); Study of loss minimization techniques including core lamination; Discussion of practical transformer efficiency; Step-by-step solution of Example 6 (complex power transmission system); Analysis of step-up and step-down transformer roles

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 105-108

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