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
Potential Difference and Voltage Measurement

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
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:
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
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

Multiple ammeters
-Bulbs
-Connecting wires
-Dry cells
-Switches
-Circuit boards
-Calculator
-Current distribution worksheets
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 130-133
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
Types of Resistors and Their Applications

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
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:
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
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

Filament bulbs
-Diodes
-Thermistors
-LDR
-Ammeter
-Voltmeter
-Rheostat
-Graph paper
-Various conductors for testing
Various resistor types
-Color code charts
-Rheostat
-Potentiometer
-Thermistor
-LDR
-Multimeter
-Circuit boards
-Application examples

KLB Secondary Physics Form 3, Pages 134-135
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
Resistors in Series - Theory and Calculations

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

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

KLB Secondary Physics Form 3, Pages 142-144

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
Electromotive Force (EMF) and Terminal Voltage

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

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

KLB Secondary Physics Form 3, Pages 150-153
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

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

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

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

Heating Effect of Electric Current

Electrical power and energy calculations
Applications - electrical lighting and heating devices

By the end of the lesson, the learner should be able to:
Define electrical power P = VI = I²R = V²/R
- Calculate electrical energy W = Pt
- Convert between different units (J, kWh)
- Solve complex power problems

In groups, learners are guided to:
Derivation of electrical power formulas
- Energy unit conversions
- Problem solving on household appliances
- Cost calculations for electrical consumption

Calculators, Unit conversion charts, Household appliance ratings, Electricity bills, Problem sets
Filament lamps, Electric iron, Electric kettle, Heating elements, Energy saving bulbs, Appliance diagrams

KLB Secondary Physics Form 3, Pages 201-202

Heating Effect of Electric Current

Electrical safety - fuses and circuit protection
Efficiency calculations and motor problems
Series and parallel heating circuits

By the end of the lesson, the learner should be able to:
Explain working principle of fuses
- Calculate appropriate fuse ratings
- Describe safety measures in electrical installations
- Analyze circuit protection methods

In groups, learners are guided to:
Demonstration of fuse operation
- Calculation of fuse ratings for appliances
- Discussion on electrical safety
- Analysis of circuit protection devices

Various fuses, Fuse holders, Circuit diagrams, Safety equipment demonstrations, Rating calculations
Motor specifications, Efficiency calculation worksheets, Power meters, Mechanical loading systems
Resistors in circuits, Ammeters, Voltmeters, Power calculation sheets, Circuit boards

KLB Secondary Physics Form 3, Pages 203-204

Quantity of Heat

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

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

KLB Secondary Physics Form 3, Pages 206-209

Quantity of Heat

Determination of specific heat capacity - electrical method
Specific heat capacity of liquids and continuous flow method
Change of state and latent heat concepts
Specific latent heat of fusion

By the end of the lesson, the learner should be able to:
Describe electrical method for solids
- Perform electrical heating experiment
- Calculate electrical energy supplied
- Determine specific heat capacity using electrical method
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 using electrical heating of metal block
- Measurement of voltage, current and time
- Calculation of electrical energy supplied
- Determination of specific heat capacity
Experiment plotting cooling curve for naphthalene
- Observation of temperature plateaus during phase changes
- Discussion on latent heat concept
- Graph analysis and interpretation

Metal cylinder with heater, Voltmeter, Ammeter, Thermometer, Stopwatch, Insulating materials, Power supply
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

KLB Secondary Physics Form 3, Pages 212-214
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
Gas Laws

Evaporation and cooling effects
Introduction to gas behavior and Boyle's Law

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
Syringes, J-shaped tubes, Oil, Bourdon gauge, Foot pump, Metre rule, Graph paper

KLB Secondary Physics Form 3, Pages 230-233

Gas Laws

Boyle's Law experiments and calculations
Boyle's Law applications and kinetic theory explanation

By the end of the lesson, the learner should be able to:
Perform experiment to verify Boyle's Law
- Record pressure and volume data
- Plot graphs of P vs V, P vs 1/V, and PV vs P
- Calculate pressure-volume products and verify constant relationship

In groups, learners are guided to:
Experiment using J-shaped tube with oil and pressure measurement
- Data collection and tabulation
- Graph plotting and analysis
- Verification of PV = constant relationship

Thick-walled J-shaped tube, Oil, Pressure gauge, Measuring instruments, Data tables, Graph paper, Calculators
Problem worksheets, Kinetic theory diagrams, Calculator, Gas bubble scenarios, Atmospheric pressure data

KLB Secondary Physics Form 3, Pages 235-238

Gas Laws

Charles's Law
Charles's Law applications and absolute temperature scale
Pressure Law (Gay-Lussac's Law)
Combined gas laws and ideal gas behavior

By the end of the lesson, the learner should be able to:
State Charles's Law for constant pressure processes
- Demonstrate volume-temperature relationship
- Perform experiments to verify V ∝ T relationship
- Plot V vs T and V vs θ graphs
State relationship between pressure and temperature at constant volume
- Demonstrate pressure-temperature experiments
- Verify P ∝ T relationship
- Derive pressure law formula

In groups, learners are guided to:
Experiment using gas column in tube with varying temperature
- Temperature and volume measurements
- Graph plotting showing linear relationship
- Discussion on absolute zero concept
Experiment using constant volume gas with temperature variation
- Pressure measurements at different temperatures
- Graph plotting of P vs T
- Verification of linear relationship through origin

Gas tubes, Water baths, Thermometers, Measuring cylinders, Heating apparatus, Graph paper, Temperature control equipment
Temperature conversion charts, Problem sets, Calculators, Hot air balloon examples, Gas heating scenarios
Constant volume gas apparatus, Pressure gauges, Temperature control, Water baths, Thermometers, Graph materials
Combined law worksheets, Complex problem sets, Calculators, Ideal gas assumption charts

KLB Secondary Physics Form 3, Pages 238-241
KLB Secondary Physics Form 3, Pages 242-244

Gas Laws

Kinetic theory of gases
Absolute zero and temperature scales

By the end of the lesson, the learner should be able to:
State basic assumptions of kinetic theory
- Explain gas laws using molecular motion
- Relate temperature to average kinetic energy
- Analyze molecular behavior in different conditions

In groups, learners are guided to:
Discussion of kinetic theory postulates
- Molecular explanation of gas laws
- Mathematical relationship between temperature and kinetic energy
- Analysis of molecular motion at different temperatures

Kinetic theory diagrams, Molecular motion animations, Temperature-energy relationship charts, Theoretical discussion materials
Graph paper, Extrapolation exercises, Temperature scale diagrams, Conversion worksheets, Scientific calculators

KLB Secondary Physics Form 3, Pages 244-245

Gas Laws

Comprehensive applications and problem solving

By the end of the lesson, the learner should be able to:
Solve complex multi-step gas law problems
- Apply gas laws to real-world situations
- Analyze atmospheric and weather-related phenomena
- Review all gas law concepts and applications

In groups, learners are guided to:
Comprehensive problem solving session
- Analysis of weather balloons, scuba diving, and atmospheric pressure effects
- Review of all gas laws
- Preparation for examinations with complex scenarios

Past examination papers, Multi-step problem sets, Real-world scenario worksheets, Summary charts, Calculators

KLB Secondary Physics Form 3, Pages 235-245