Current Electricity (II)

Ohmic and Non-Ohmic Conductors

By the end of the lesson, the learner should be able to:
Distinguish between ohmic and non-ohmic conductors
-Investigate V-I characteristics of different materials
-Understand why some materials don't obey Ohm's law
-Analyze V-I graphs for various conductors
-Identify practical applications of non-ohmic conductors

In groups, learners are guided to:
Q/A on Ohm's law applications
-Experiment: V-I characteristics of filament bulb
-Experiment: V-I characteristics of diode
-Comparison of different V-I graph shapes
-Discussion on temperature effects on resistance
-Applications of non-ohmic conductors

Filament bulbs
-Diodes
-Thermistors
-LDR
-Ammeter
-Voltmeter
-Rheostat
-Graph paper
-Various conductors for testing

KLB Secondary Physics Form 3, Pages 134-135

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

In groups, learners are guided to:
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
Wheatstone Bridge Method
Resistors in Series - Theory and Calculations

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
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

In groups, learners are guided to:
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
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

Unknown resistors
-Voltmeter
-Ammeter
-Rheostat
-Connecting wires
-Dry cells
-Switches
-Calculator
-Multimeter for comparison
Wheatstone bridge apparatus
-Galvanometer
-Known resistors
-Unknown resistors
-Battery
-Bridge equation charts
Resistors of known values
-Multimeter
-Connecting wires
-Circuit boards
-Calculator
-Series circuit diagrams
-Problem worksheets

KLB Secondary Physics Form 3, Pages 140-142
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

In groups, learners are guided to:
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

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

In groups, learners are guided to:
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

KLB Secondary Physics Form 3, Pages 150-153

Current Electricity (II)

Electromotive Force (EMF) and Terminal Voltage

By the end of the lesson, the learner should be able to:
Define electromotive force (EMF)
-Distinguish between EMF and terminal voltage
-Understand the concept of lost voltage
-Relate EMF to work done by the cell
-Measure EMF using high resistance voltmeter

In groups, learners are guided to:
Review mixed circuits through Q/A
-Definition of EMF as work done per unit charge
-Demonstration: measuring EMF with open circuit
-Comparison of EMF and terminal voltage under load
-Discussion on energy conversion in cells
-Measurement techniques for EMF

High resistance voltmeter
-Various cells
-Switches
-Resistors
-Connecting wires
-EMF measurement setup
-Energy conversion charts

KLB Secondary Physics Form 3, Pages 150-152

Current Electricity (II)

Internal Resistance of Cells
Cells in Series and Parallel
Advanced Circuit Analysis and Problem Solving

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
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

In groups, learners are guided to:
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
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

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

KLB Secondary Physics Form 3, Pages 150-153
KLB Secondary Physics Form 3, Pages 152-153

Waves II

Properties of waves
Reflection of waves

By the end of the lesson, the learner should be able to:
Define wavelength, frequency, amplitude and wavefront
- Explain rectilinear propagation of waves
- Describe wave production in ripple tank
- Calculate wave speed using v=fλ

In groups, learners are guided to:
Q/A on wave basics from Form 2
- Demonstration of wave production using ripple tank
- Observation of rectilinear propagation
- Calculations on wave speed

Ripple tank, Straight vibrator, Water, Rulers, Stroboscope, Charts on wave properties
Ripple tank, Plane wave generator, Curved and straight reflectors, Graph paper, Pencils

KLB Secondary Physics Form 3, Pages 156-158

Waves II

Refraction of waves
Diffraction of waves

By the end of the lesson, the learner should be able to:
Describe refraction when waves change medium
- Explain change in wavelength and speed
- Demonstrate refraction using shallow and deep regions
- State that frequency remains constant

In groups, learners are guided to:
Q/A on refraction basics
- Experiment using glass plate to create shallow region
- Observation of wavefront spacing changes
- Discussion on speed and wavelength changes

Ripple tank, Glass plates, Water, Rulers for measurement, Frequency generator
Ripple tank, Barriers with gaps, Various gap sizes, Measuring instruments, Wave generator

KLB Secondary Physics Form 3, Pages 161-163

Waves II

Interference patterns
Constructive and destructive interference

By the end of the lesson, the learner should be able to:
Define interference and superposition principle
- Explain constructive and destructive interference
- Describe formation of interference patterns
- Calculate path differences

In groups, learners are guided to:
Demonstration using two coherent sources
- Construction of interference patterns on paper
- Observation of nodal and antinodal lines
- Discussion on coherent sources

Two-point sources, Graph paper, Compass, Rulers, Ripple tank setup, Audio frequency generator
Two loudspeakers, Audio generator, Microphone, Sound level meter, Connecting wires

KLB Secondary Physics Form 3, Pages 165-167

Waves II

Stationary waves formation
Modes of vibration in strings
Vibrating air columns - closed pipes
Vibrating air columns - open pipes

By the end of the lesson, the learner should be able to:
Define stationary waves
- Explain formation from two opposing waves
- Identify nodes and antinodes
- Calculate distances between nodes
Compare open and closed pipe resonance
- Derive frequency formulas for open pipes
- Explain harmonic series differences
- Solve numerical problems

In groups, learners are guided to:
Demonstration using vibrating string
- Setup with tuning fork and pulley
- Observation of stationary wave patterns
- Measurements of wavelength
Experiment with open pipe resonance
- Comparison with closed pipe results
- Mathematical problem solving
- Summary of all wave phenomena

Tuning fork, String, Pulley, Weights, Stroboscope, Measuring tape, Retort stands
Sonometer, Tuning forks, Weights, Measuring instruments, Calculator, Formula charts
Closed pipes of various lengths, Tuning forks, Water, Measuring cylinders, Resonance tubes
Open pipes, Tuning forks, Sound level meters, Calculators, Summary charts, Past papers

KLB Secondary Physics Form 3, Pages 167-170
KLB Secondary Physics Form 3, Pages 174-176

Electrostatics II

Electric field patterns and charge distribution
Lightning arrestor and capacitance introduction

By the end of the lesson, the learner should be able to:
Define electric field and electric field lines
- Demonstrate field patterns using chalk dust method
- Describe charge distribution on spherical and pear-shaped conductors
- Use proof-plane and electroscope to test charge distribution

In groups, learners are guided to:
Q/A on electrostatics basics from Form 2
- Experiment using chalk dust in castor oil to show field patterns
- Investigation of charge distribution using proof-plane
- Observation of electroscope deflections at different conductor points

High voltage source, Wire electrodes, Petri-dish, Castor oil, Chalk dust, Spherical and pear-shaped conductors, Proof-plane, Gold-leaf electroscope
Wind-mill model, Point charges, Lightning arrestor photos, Parallel-plate capacitors, Battery, Voltmeter, Milliammeter

KLB Secondary Physics Form 3, Pages 177-181

Electrostatics II

Factors affecting capacitance and types of capacitors
Capacitors in series and parallel
Energy stored in capacitors

By the end of the lesson, the learner should be able to:
Investigate effect of plate separation, area and dielectric on capacitance
- Derive capacitance formula C = εA/d
- Describe paper, electrolytic and variable capacitors
- Explain construction principles

In groups, learners are guided to:
Experiment varying plate separation and area
- Investigation using different dielectric materials
- Mathematical derivation of capacitance formula
- Examination of different capacitor types and their construction

Aluminium plates, Various dielectric materials, Electroscope, Paper capacitors, Electrolytic capacitors, Variable air capacitors, Measuring instruments
Capacitors of different values, Voltmeters, Ammeters, Battery, Connecting wires, Calculators, Circuit boards
Charged capacitors, Energy calculation worksheets, Graphing materials, Calculators, Safety equipment

KLB Secondary Physics Form 3, Pages 185-188

Electrostatics II

Complex capacitor problems
Applications of capacitors

By the end of the lesson, the learner should be able to:
Solve problems involving mixed series and parallel combinations
- Calculate charges, voltages and energies in complex circuits
- Apply energy conservation principles
- Analyze capacitor charging and discharging

In groups, learners are guided to:
Problem solving with complex capacitor networks
- Analysis of charging and discharging processes
- Energy transfer calculations
- Graph interpretation of charging curves

Complex circuit diagrams, Advanced problem worksheets, Graphing materials, Calculators, Past examination papers
Circuit diagrams, Smoothing circuit demo, Radio tuning circuits, Camera flash unit, Revision charts, Past examination papers

KLB Secondary Physics Form 3, Pages 188-193

Heating Effect of Electric Current

Introduction to heating effect
Factors affecting heat produced - current and time
Factors affecting heat produced - resistance
Joule's law and electrical energy
Electrical power and energy calculations

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
Investigate relationship between heat produced and resistance
- Compare heating in different resistance wires
- State H ∝ R relationship
- Derive complete heating formula H = I²Rt

In groups, learners are guided to:
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
Experiment using coils of different resistance
- Temperature measurements with constant current
- Comparison of heating rates
- Mathematical derivation of heating law

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
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 195-197
KLB Secondary Physics Form 3, Pages 199-200

Heating Effect of Electric Current

Applications - electrical lighting and heating devices
Electrical safety - fuses and circuit protection

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

In groups, learners are guided to:
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

KLB Secondary Physics Form 3, Pages 202-203

Heating Effect of Electric Current

Efficiency calculations and motor problems
Series and parallel heating circuits

By the end of the lesson, the learner should be able to:
Calculate efficiency of electrical devices
- Solve problems involving motors and mechanical work
- Analyze power input vs power output
- Calculate overall efficiency in systems

In groups, learners are guided to:
Problem solving on device efficiency
- Motor efficiency calculations
- Analysis of energy conversions
- Real-world efficiency problems

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 201-204

Quantity of Heat

Heat capacity and specific heat capacity
Determination of specific heat capacity - method of mixtures for solids
Determination of specific heat capacity - electrical method

By the end of the lesson, the learner should be able to:
Define heat capacity and specific heat capacity
- State SI units for both quantities
- Distinguish between heat capacity and specific heat capacity
- Use formula Q = mcθ in simple calculations

In groups, learners are guided to:
Q/A on heat concepts from previous studies
- Discussion on definitions and units
- Comparison of heat capacity vs specific heat capacity
- Simple problem solving using Q = mcθ formula

Charts on heat definitions, Calculators, Simple problem worksheets, Various materials for comparison
Metal blocks, Beakers, Water, Thermometers, Weighing balance, Heat source, Well-lagged calorimeter, Stirrer
Metal cylinder with heater, Voltmeter, Ammeter, Thermometer, Stopwatch, Insulating materials, Power supply

KLB Secondary Physics Form 3, Pages 206-209

Quantity of Heat

Specific heat capacity of liquids and continuous flow method
Change of state and latent heat concepts
Specific latent heat of fusion
Specific latent heat of vaporization

By the end of the lesson, the learner should be able to:
Determine specific heat capacity of water by electrical method
- Describe continuous flow method
- Explain advantages of continuous flow method
- Solve problems on specific heat capacity
Define specific latent heat of fusion
- Determine latent heat of ice by method of mixtures
- Perform electrical method for latent heat
- Calculate latent heat from experimental data

In groups, learners are guided to:
Electrical method experiment for water
- Discussion on continuous flow apparatus
- Analysis of method advantages
- Problem solving on specific heat calculations
Method of mixtures experiment using ice and warm water
- Electrical method using ice and immersion heater
- Heat balance calculations
- Determination of specific latent heat values

Calorimeter, Electrical heater, Water, Measuring instruments, Continuous flow apparatus diagram, Problem sets
Naphthalene, Test tubes, Thermometer, Stopwatch, Graph paper, Heat source, Cooling apparatus
Ice, Calorimeter, Thermometer, Electrical heater, Filter funnels, Beakers, Measuring cylinders
Steam generator, Condenser, Calorimeter, Electrical heater, Measuring instruments, Safety equipment

KLB Secondary Physics Form 3, Pages 214-217
KLB Secondary Physics Form 3, Pages 220-223

Quantity of Heat

Effects of pressure and impurities on melting and boiling points
Evaporation and cooling effects

By the end of the lesson, the learner should be able to:
Investigate effect of pressure on melting point of ice
- Demonstrate regelation phenomenon
- Investigate effect of pressure on boiling point
- Explain effect of impurities on phase transition temperatures

In groups, learners are guided to:
Regelation experiment with ice and wire
- Pressure effect on boiling point using flask
- Salt solution boiling point investigation
- Discussion on pressure cooker working

Ice blocks, Weighted wire, Round-bottomed flask, Thermometer, Salt solutions, Pressure cooker model
Various liquids, Beakers, Fans, Thermometers, Ether, Test tubes, Humidity measuring devices

KLB Secondary Physics Form 3, Pages 227-230