Current Electricity (II)

Electric Current and Measurement

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

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

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

KLB Secondary Physics Form 3, Pages 126-130

Current Electricity (II)

Series and Parallel Circuits - Current Distribution

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

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

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

KLB Secondary Physics Form 3, Pages 130-133

Current Electricity (II)

Potential Difference and Voltage Measurement

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

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

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

KLB Secondary Physics Form 3, Pages 126-129

Current Electricity (II)

Series and Parallel Circuits - Voltage Distribution

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

In groups, learners are guided to:
Review voltage measurement through Q/A
-Experiment: measuring voltage across series components
-Experiment: measuring voltage across parallel components
-Analysis of voltage readings and patterns
-Statement of Kirchhoff's voltage law
-Problem-solving on voltage distribution

Multiple voltmeters
-Various resistors
-Connecting wires
-Dry cells
-Switches
-Circuit boards
-Calculator
-Voltage distribution worksheets

KLB Secondary Physics Form 3, Pages 130-133

Current Electricity (II)

Ohm's Law - Investigation and Verification

By the end of the lesson, the learner should be able to:
State Ohm's law
-Investigate relationship between voltage and current
-Plot V-I graphs for ohmic conductors
-Verify Ohm's law experimentally
-Understand conditions for Ohm's law validity

In groups, learners are guided to:
Q/A on voltage distribution
-Experiment: varying voltage and measuring current through resistor
-Data collection and table completion
-Plotting V-I graph and analyzing slope
-Statement and verification of Ohm's law
-Discussion on temperature and other conditions

Rheostat
-Ammeter
-Voltmeter
-Resistor coils
-Connecting wires
-Dry cells
-Graph paper
-Calculator
-Ruler

KLB Secondary Physics Form 3, Pages 131-135

Current Electricity (II)

Electrical Resistance and Ohm's Law Applications

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

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

Calculator
-Ohm's law triangle charts
-Resistor color code charts
-Various resistors
-Multimeter
-Problem worksheets
-Unit conversion charts

KLB Secondary Physics Form 3, Pages 131-135

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

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

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

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

KLB Secondary Physics Form 3, Pages 140-142

Current Electricity (II)

Wheatstone Bridge Method

By the end of the lesson, the learner should be able to:
Understand the principle of Wheatstone bridge
-Set up Wheatstone bridge circuit
-Balance the bridge for resistance measurement
-Calculate unknown resistance using bridge equation
-Appreciate accuracy of Wheatstone bridge method

In groups, learners are guided to:
Review voltmeter-ammeter method through Q/A
-Introduction to Wheatstone bridge principle
-Demonstration of bridge balance condition
-Setup and operation of Wheatstone bridge
-Calculation using R₁/R₂ = R₃/R₄
-Comparison of accuracy with other methods

Wheatstone bridge apparatus
-Galvanometer
-Known resistors
-Unknown resistors
-Connecting wires
-Battery
-Calculator
-Bridge equation charts

KLB Secondary Physics Form 3, Pages 142-144

Current Electricity (II)

Resistors in Series - Theory and Calculations

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

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

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

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

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

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

KLB Secondary Physics Form 3, Pages 150-153

Current Electricity (II)

Cells in Series and Parallel

By the end of the lesson, the learner should be able to:
Analyze cells connected in series
-Analyze cells connected in parallel
-Calculate total EMF and internal resistance
-Understand advantages of different connections
-Solve problems involving cell combinations

In groups, learners are guided to:
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

Multiple identical cells
-Connecting wires
-Voltmeter
-Ammeter
-Resistors
-Calculator
-Cell combination diagrams
-Problem worksheets

KLB Secondary Physics Form 3, Pages 152-153

Current Electricity (II)

Advanced Circuit Analysis and Problem Solving

By the end of the lesson, the learner should be able to:
Apply Kirchhoff's laws to complex circuits
-Solve circuits with multiple sources
-Analyze circuits with internal resistance
-Use systematic approaches to circuit problems
-Integrate all electricity concepts

In groups, learners are guided to:
Q/A on cell combinations
-Application of Kirchhoff's current and voltage laws
-Systematic approach to complex circuit analysis
-Worked examples with multiple EMF sources
-Problem-solving session covering all electricity topics
-Discussion on practical circuit applications

Complex circuit examples
-Calculator
-Circuit analysis worksheets
-Multiple EMF sources
-Various resistors
-Comprehensive problem sets
-Kirchhoff's law charts

KLB Secondary Physics Form 3, Pages 126-153

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
Derive effective capacitance for series combination
- Derive effective capacitance for parallel combination
- Explain charge and voltage relationships
- Calculate individual charges and voltages

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
Mathematical derivation of series formula (1/C = 1/C₁ + 1/C₂)
- Mathematical derivation of parallel formula (C = C₁ + C₂)
- Problem solving with capacitor combinations
- Practical verification using circuits

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
KLB Secondary Physics Form 3, Pages 188-191

Electrostatics II

Complex capacitor problems

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

KLB Secondary Physics Form 3, Pages 188-193

Electrostatics II
Heating Effect of Electric Current

Applications of capacitors
Electrical safety - fuses and circuit protection

By the end of the lesson, the learner should be able to:
Explain use in rectification and smoothing circuits
- Describe applications in tuning circuits
- State use in delay circuits and camera flash
- Solve comprehensive numerical problems on all topics

In groups, learners are guided to:
Discussion on practical applications in electronics
- Demonstration of smoothing circuits
- Explanation of tuning and delay functions
- Comprehensive revision and problem solving covering all electrostatics topics

Circuit diagrams, Smoothing circuit demo, Radio tuning circuits, Camera flash unit, Revision charts, Past examination papers
Various fuses, Fuse holders, Circuit diagrams, Safety equipment demonstrations, Rating calculations

KLB Secondary Physics Form 3, Pages 192-193

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
Describe method of mixtures for solids
- Perform experiment to determine specific heat capacity of metal
- Apply heat balance principle
- Calculate specific heat capacity from experimental data

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
Experiment using hot metal block in cold water
- Measurement of temperatures and masses
- Application of heat balance equation
- Calculation of specific heat capacity from results

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
KLB Secondary Physics Form 3, Pages 209-212

Quantity of Heat

Specific heat capacity of liquids and continuous flow method

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

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

Calorimeter, Electrical heater, Water, Measuring instruments, Continuous flow apparatus diagram, Problem sets

KLB Secondary Physics Form 3, Pages 214-217

Quantity of Heat

Change of state and latent heat concepts
Specific latent heat of fusion

By the end of the lesson, the learner should be able to:
Define latent heat of fusion and vaporization
- Explain change of state process
- Plot cooling curve for naphthalene
- Identify melting and boiling points from graphs

In groups, learners are guided to:
Experiment plotting cooling curve for naphthalene
- Observation of temperature plateaus during phase changes
- Discussion on latent heat concept
- Graph analysis and interpretation

Naphthalene, Test tubes, Thermometer, Stopwatch, Graph paper, Heat source, Cooling apparatus
Ice, Calorimeter, Thermometer, Electrical heater, Filter funnels, Beakers, Measuring cylinders

KLB Secondary Physics Form 3, Pages 218-220

Quantity of Heat

Specific latent heat of vaporization
Effects of pressure and impurities on melting and boiling points

By the end of the lesson, the learner should be able to:
Define specific latent heat of vaporization
- Determine latent heat of steam by condensation method
- Perform electrical method for vaporization
- Solve complex latent heat problems

In groups, learners are guided to:
Steam condensation experiment in calorimeter
- Electrical method using boiling water
- Calculation of latent heat of vaporization
- Complex problem solving involving phase changes

Steam generator, Condenser, Calorimeter, Electrical heater, Measuring instruments, Safety equipment
Ice blocks, Weighted wire, Round-bottomed flask, Thermometer, Salt solutions, Pressure cooker model

KLB Secondary Physics Form 3, Pages 223-227

Quantity of Heat

Evaporation and cooling effects

By the end of the lesson, the learner should be able to:
Define evaporation and distinguish from boiling
- Investigate factors affecting evaporation rate
- Demonstrate cooling effect of evaporation
- Explain applications of evaporation cooling

In groups, learners are guided to:
Experiments on evaporation rate factors
- Demonstration of cooling by evaporation using ether
- Investigation of surface area, temperature and humidity effects
- Discussion on natural cooling systems

Various liquids, Beakers, Fans, Thermometers, Ether, Test tubes, Humidity measuring devices

KLB Secondary Physics Form 3, Pages 230-233