Lesson Notes
වියාචනය (Disclaimer)
Idasara Academy ඉගෙනුම් සම්පත් නිර්මාණය කර ඇත්තේ සිසුන්ට මගපෙන්වීම, පුහුණුව සහ අධ්යයන උපායමාර්ග ලබාදී සහයෝගය දැක්වීමටය.
කෙසේ වෙතත්, සියලුම විභාග සහ නිල අවශ්යතා සඳහා, සිසුන් අනිවාර්යයෙන්ම ශ්රී ලංකා අධ්යාපන අමාත්යාංශයේ, අධ්යාපන ප්රකාශන දෙපාර්තමේන්තුව විසින් ප්රකාශයට පත් කරන ලද නිල පෙළපොත් සහ සම්පත් පරිශීලනය කළ යුතුය.
ජාතික විභාග සඳහා අන්තර්ගතයේ නිල බලය ලත් මූලාශ්රය වනුයේ රජය විසින් නිකුත් කරනු ලබන මෙම ප්රකාශනයි.
Grade 12
First Term
Second Term
Third Term
Grade 13
Second Term
Grade
12
Lesson 1.1 – Scientific Method & Scope of Physics
Foundation (Q1–5)
What is physics? Give one example of its application.
List the steps of the scientific method.
Define “hypothesis.”
Give two examples of observations in everyday life.
What is a scientific law?
Intermediate (Q6–10)
Explain the difference between a hypothesis and a theory.
Why is experimentation important in physics?
Give an example of a situation where prediction is used in science.
Describe how measurement improves scientific observations.
Explain the importance of repeatability in experiments.
Advanced (Q11–15)
Provide a full example of applying the scientific method to investigate pendulum motion.
Explain why scientific models are essential and give one example.
Compare a scientific theory and a law with two differences.
Identify and correct flaws in a poorly designed experiment (your own scenario).
Discuss why controlled variables are crucial in an investigation.
Lesson 1.2 – Physical Quantities & SI Units
Foundation (Q1–5)
Define a physical quantity.
What is the SI unit of mass?
State two derived quantities.
Distinguish between base and derived quantities.
Write the SI units of force and energy.
Intermediate (Q6–10)
Convert 5 km to meters.
Explain why units are important in calculations.
What is meant by “SI prefix”? Give two examples.
Convert 2.5 hours to seconds.
List base quantities involved in defining Newton (N).
Advanced (Q11–15)
Express 3.2×10⁶ g in kg using correct prefixes.
Show how pressure (Pa) is derived from base units.
Convert 0.05 m³ to cm³.
Explain consequences of inconsistent unit usage in an experiment.
Create a complex conversion involving time, mass, and length (your own values) and solve it.
Lesson 1.3 – Dimensions & Dimensional Analysis
Foundation (Q1–5)
What are dimensions? Give an example.
Write the dimensions of velocity.
State the dimensions of force.
What is dimensional homogeneity?
Identify whether energy has dimensions.
Intermediate (Q6–10)
Show that momentum has dimensions of MLT⁻¹.
Use dimensional analysis to check if the formula v = u + at is correct.
Write dimensional formula for pressure.
Evaluate whether the relation KE = ½mv³ is dimensionally correct.
Derive dimensions of power.
Advanced (Q11–15)
Use dimensional analysis to derive the formula for the period of a simple pendulum.
Explain why dimensional analysis cannot determine numerical constants.
Show that G (gravitational constant) has dimensions of M⁻¹L³T⁻².
Derive the dimensions of viscosity.
Determine whether equation s = ut² + ½at is dimensionally correct and justify.
Lesson 1.4 – Measuring Instruments & Errors
Foundation (Q1–5)
Give one instrument used for measuring small lengths.
Define least count.
What is a zero error?
Name two types of errors.
What is a random error?
Intermediate (Q6–10)
A screw gauge has pitch 0.5 mm and 100 divisions. Find least count.
Explain how to correct zero error in Vernier caliper.
A length is measured as 14.5 ± 0.1 cm. Find percentage error.
Distinguish systematic and random errors.
Explain why repeated measurements improve accuracy.
Advanced (Q11–15)
Analyse a given Vernier scale reading and calculate true length.
Explain how environmental factors contribute to systematic errors.
Describe an experiment to measure diameter of a wire with minimum error.
Discuss why human reaction time affects time measurements.
A student records inconsistent data. Identify likely sources of error and propose corrections.
Lesson 1.5 – Vectors & Resolution
Foundation (Q1–5)
Define vector quantity.
Give three examples of vectors.
Draw a vector with magnitude 5 units.
What is meant by direction of a vector?
State head-to-tail rule.
Intermediate (Q6–10)
Resolve 12 N force at 30° into components.
Illustrate parallelogram law with diagram.
Distinguish vector and scalar with examples.
Two forces 5 N and 12 N act at right angles. Find resultant.
Define unit vector.
Advanced (Q11–15)
Solve vector addition involving three forces using head-to-tail method.
A force F makes 40° with horizontal. Find Fx and Fy.
Given vectors A = (3,4) and B = (1,2), compute A + B and magnitude.
Explain how vectors are used in projectile motion.
Determine equilibrium condition for three vectors forming a closed triangle.
Lesson 1.6 – Graphs & Data Interpretation
Foundation (Q1–5)
What is a graph?
Define dependent and independent variables.
What does slope of a graph represent?
What is a linear graph?
Label axes on a sample graph.
Intermediate (Q6–10)
A displacement–time graph has slope 4. What is velocity?
Identify uniform acceleration from velocity–time graph.
Draw a v–t graph for an object accelerating uniformly.
What does area under v–t graph represent?
Explain why correct scaling is important.
Advanced (Q11–15)
Interpret a multi-section v–t graph and find displacement.
Compare two graphs showing motion of two cars.
Identify experimental errors from anomalies on graph.
Explain significance of non-linear graphs in real-world physics.
Given experimental data, construct best-fit line and compute slope.
