SS 1

Revision – Second Term

Physics SS 1 Second Term (Week 10)

📌 Welcome to Your Second Term Revision!

This comprehensive revision covers all the topics from the Second Term. Use this to:

Review key concepts from each topic (Weeks 2–9).
Practice with mixed revision questions.
Prepare for your end-of-term examination.
Identify areas that need more attention.

Topics Covered in Second Term

Week	Topic	Key Concepts
2	Pressure	P = F/A, P = ρgh, atmospheric pressure, Pascal's Principle, barometer, manometer, hydraulic press.
3	Density and Relative Density	ρ = m/V, R.D. = ρ_substance/ρ_water, measuring density (regular/irregular/liquids), density bottle, Archimedes' principle.
4	Heat I – Temperature & Thermometers	Temperature vs heat, thermometric properties, types of thermometers, Celsius/Fahrenheit/Kelvin scales, conversion formulas, calibration, mercury vs alcohol.
5	Heat II – Thermal Expansion	ΔL = αL₀ΔT, β ≈ 2α, γ ≈ 3α, anomalous expansion of water, applications (bimetallic strip, gaps), consequences.
6	Heat III – Thermal Conductivity	k (W/m·K), Q/t = kAΔT/L, good vs bad conductors, factors affecting conductivity, Fourier's Law, applications.
7	Heat IV – Latent Heat	L_f = Q/m, L_v = Q/m, heating/cooling curves, phase changes, applications (refrigeration, sweating, steam).
8	Heat V – Gas Laws	Boyle's Law (P₁V₁ = P₂V₂), Charles's Law (V₁/T₁ = V₂/T₂), Pressure Law (P₁/T₁ = P₂/T₂), Combined Gas Law (P₁V₁/T₁ = P₂V₂/T₂), PV = nRT.
9	Light I – Reflection	Rectilinear propagation, laws of reflection (i = r), specular vs diffuse reflection, plane mirrors, real vs virtual images, lateral inversion.

Summary Diagram – All Topics

Second Term Topics – Summary

Key Formula Summary

Topic	Formula	Variables
Pressure	P = F/A	F = force, A = area
Pressure in Fluids	P = ρgh	ρ = density, g = gravity, h = depth
Density	ρ = m/V	m = mass, V = volume
Relative Density	R.D. = ρ_substance/ρ_water	ρ_water = 1000 kg/m³
Thermal Expansion (Linear)	ΔL = αL₀ΔT	α = coeff. of linear expansion
Thermal Conductivity	Q/t = kAΔT/L	k = thermal conductivity
Latent Heat of Fusion	L_f = Q/m	Q = heat energy, m = mass
Latent Heat of Vaporization	L_v = Q/m	Q = heat energy, m = mass
Boyle's Law	P₁V₁ = P₂V₂	T = constant
Charles's Law	V₁/T₁ = V₂/T₂	P = constant
Pressure Law	P₁/T₁ = P₂/T₂	V = constant
Combined Gas Law	P₁V₁/T₁ = P₂V₂/T₂	n = constant
General Gas Equation	PV = nRT	R = 8.314 J/mol·K
Reflection	i = r	i = angle of incidence, r = angle of reflection
Number of Images	n = 360°/θ − 1	θ = angle between mirrors
Temperature Conversion	°F = (°C × 9/5) + 32	—
Temperature Conversion	K = °C + 273.15	—

Topic-by-Topic Revision

Week 2: Pressure

🔑 Key Points:

Pressure = Force / Area (P = F/A). Unit: Pascal (Pa).
Pressure in fluids: P = ρgh. Increases with depth.
Atmospheric pressure at sea level = 101,325 Pa.
Pascal's Principle: Pressure applied to a confined fluid is transmitted equally in all directions.
Applications: Hydraulic press, barometer, manometer.

Week 3: Density and Relative Density

🔑 Key Points:

Density = Mass / Volume (ρ = m/V). Unit: kg/m³.
Relative Density = ρ_substance / ρ_water (no units).
Density of water = 1000 kg/m³.
Methods: Regular objects (geometric), Irregular objects (water displacement), Liquids (density bottle).
Applications: Hydrometer, ships, hot air balloons.

Week 4: Temperature and Thermometers

🔑 Key Points:

Temperature ≠ Heat. Temperature = average kinetic energy.
Thermometric properties: expansion, resistance, pressure, voltage.
Scales: Celsius (°C), Fahrenheit (°F), Kelvin (K).
Conversions: °F = (°C × 9/5) + 32; K = °C + 273.15.
Mercury: high boiling point, uniform expansion, toxic. Alcohol: low freezing point, cheap.

Week 5: Thermal Expansion

🔑 Key Points:

Linear: ΔL = αL₀ΔT. Area: β ≈ 2α. Volume: γ ≈ 3α.
Anomalous expansion of water: maximum density at 4°C.
Applications: Bimetallic strip (thermostats), expansion gaps, thermometers, hot air balloons.
Consequences: Buckling, cracking, bursting pipes.

Week 6: Thermal Conductivity

🔑 Key Points:

Good conductors: Metals (silver, copper, aluminium).
Insulators: Wood, glass, rubber, plastic, air.
Fourier's Law: Q/t = kAΔT/L.
Factors: Material type, temperature, density, purity, physical state.
Applications: Cooking pots, heat sinks, thermos flasks, building insulation.

Week 7: Latent Heat

🔑 Key Points:

Latent heat: Hidden heat during phase change (no temperature change).
L_f = Q/m (fusion: solid ↔ liquid). Water L_f = 3.34 × 10⁵ J/kg.
L_v = Q/m (vaporization: liquid ↔ gas). Water L_v = 2.26 × 10⁶ J/kg.
Heating curve: Flat sections at melting and boiling points.
Applications: Refrigeration, sweating, steam cooking, ice cooling.

Week 8: Gas Laws

🔑 Key Points:

Boyle's Law: P₁V₁ = P₂V₂ (constant T).
Charles's Law: V₁/T₁ = V₂/T₂ (constant P).
Pressure Law: P₁/T₁ = P₂/T₂ (constant V).
Combined: P₁V₁/T₁ = P₂V₂/T₂.
General: PV = nRT.
Temperature must be in KELVIN.

Week 9: Light – Reflection

🔑 Key Points:

Light travels in straight lines (rectilinear propagation).
Laws: (i) Incident ray, reflected ray, normal in same plane. (ii) i = r.
Specular (smooth → clear image) vs Diffuse (rough → scattered).
Plane mirror image: Virtual, upright, same size, laterally inverted, image distance = object distance.
Real: can be projected, inverted. Virtual: cannot be projected, upright.

Mixed Revision Questions

Test your understanding of all Second Term topics:

Section A: Multiple Choice (Choose the correct option)

Pressure is defined as:
A) Force × Area B) Force / Area C) Area / Force D) Mass / Volume
The SI unit of density is:
A) kg/m³ B) g/cm³ C) kg·m³ D) N/m²
Which of the following is a good conductor of heat?
A) Wood B) Rubber C) Copper D) Glass
The latent heat of fusion is the heat required for:
A) Solid → Liquid B) Liquid → Gas C) Gas → Liquid D) Liquid → Solid
Charles's Law states that at constant pressure:
A) V ∝ 1/T B) V ∝ T C) P ∝ 1/V D) P ∝ T
A plane mirror produces an image that is:
A) Real and inverted B) Real and upright C) Virtual and upright D) Virtual and inverted
The angle of incidence equals the angle of reflection is the:
A) First Law of Reflection B) Second Law of Reflection C) Third Law of Reflection D) Law of Refraction
Water has maximum density at:
A) 0°C B) 4°C C) 100°C D) 25°C
Fourier's Law relates heat flow to:
A) P = F/A B) Q/t = kAΔT/L C) P = ρgh D) V₁/T₁ = V₂/T₂
Relative density has:
A) Units of kg/m³ B) Units of Pa C) No units D) Units of J/kg

Answers: 1-B, 2-A, 3-C, 4-A, 5-B, 6-C, 7-B, 8-B, 9-B, 10-C

Section B: Short Answer Questions

Define pressure and state its SI unit.
What is the difference between density and relative density?
State the two laws of reflection.
What is the difference between temperature and heat?
State Boyle's Law in words.
What is latent heat of vaporization?
Why does water expand when cooled below 4°C?
List three applications of thermal expansion.
What is the difference between a real image and a virtual image?
State Charles's Law mathematically.

Section C: Calculation Questions

A force of 200 N acts on an area of 0.5 m². Calculate the pressure.
A liquid has a mass of 400 g and a volume of 200 cm³. Calculate its density in g/cm³ and kg/m³.
An iron rod of length 3.0 m at 20°C is heated to 80°C. Calculate the increase in length. (α = 1.2 × 10⁻⁵ /°C)
How much heat is required to melt 2.0 kg of ice at 0°C? (L_f = 3.34 × 10⁵ J/kg)
A gas occupies 0.3 m³ at 200,000 Pa. If the pressure is increased to 300,000 Pa at constant temperature, what is the new volume?
Convert 25°C to Fahrenheit and Kelvin.
A copper plate of thickness 0.01 m and area 0.6 m² has a temperature difference of 30°C. Calculate the rate of heat flow. (k for copper = 401 W/m·K)
An object is placed 20 cm in front of a plane mirror. How far behind the mirror is the image formed?
A gas has a volume of 2.0 m³ at 27°C. What is the volume at 127°C at constant pressure?
Calculate the relative density of a substance with density 1500 kg/m³. (ρ_water = 1000 kg/m³)

Answers to Section B

1. Pressure = Force / Area. SI unit: Pascal (Pa).

2. Density is mass per unit volume (kg/m³); relative density is the ratio of density of a substance to that of water (no units).

3. (i) Incident ray, reflected ray, and normal lie in the same plane. (ii) Angle of incidence = Angle of reflection.

4. Temperature is a measure of average kinetic energy; heat is energy that flows due to temperature difference.

5. For a fixed mass of gas at constant temperature, pressure is inversely proportional to volume.

6. Latent heat of vaporization is the heat required to change a liquid to gas at its boiling point without temperature change.

7. Water has maximum density at 4°C; below 4°C, the molecular structure causes expansion as it cools.

8. Bimetallic strips, expansion gaps in bridges, thermometers, hot air balloons, metal rims on wheels.

9. Real image: actual intersection of rays, can be projected, inverted. Virtual image: apparent intersection, cannot be projected, upright.

10. V₁/T₁ = V₂/T₂.

Answers to Section C

1. P = 200 / 0.5 = 400 Pa

2. ρ = 400 / 200 = 2 g/cm³ = 2000 kg/m³

3. ΔT = 80 − 20 = 60°C; ΔL = 1.2 × 10⁻⁵ × 3.0 × 60 = 2.16 × 10⁻³ m = 2.16 mm

4. Q = 2.0 × 3.34 × 10⁵ = 6.68 × 10⁵ J (668 kJ)

5. P₁V₁ = P₂V₂ → 200,000 × 0.3 = 300,000 × V₂ → V₂ = 0.2 m³

6. °F = (25 × 9/5) + 32 = 77°F; K = 25 + 273.15 = 298.15 K

7. Q/t = 401 × 0.6 × 30 / 0.01 = 7218 / 0.01 = 721,800 W

8. Image distance = Object distance = 20 cm behind the mirror.

9. T₁ = 27 + 273 = 300 K; T₂ = 127 + 273 = 400 K; V₂ = 2.0 × 400 / 300 = 2.67 m³

10. R.D. = 1500 / 1000 = 1.5

Examination Preparation Tips

📌 Tips for Success:

Review all formulas – make a formula sheet and memorise them.
Understand key definitions – be able to explain concepts in your own words.
Practice calculations – work through all examples and assignment questions.
Know your units – be familiar with SI units for all quantities.
Use Kelvin for gas law problems – always convert °C to K.
Draw diagrams – practice drawing reflection ray diagrams and heating curves.
Know the properties of water – density at 4°C, latent heat values.
Time management – allocate time for each section during the exam.
Read questions carefully – identify what is being asked before answering.

✅ Good luck with your examination!

Remember to stay calm, read all questions carefully, and show your working clearly. You've got this! 💪

Board Summary

╔════════════════════════════════════════════════════════════════════════════╗ ║ SS1 PHYSICS – SECOND TERM REVISION ║ ╠════════════════════════════════════════════════════════════════════════════╣ ║ ║ ║ WEEK 2: PRESSURE ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ P = F/A, P = ρgh, Atmospheric pressure = 101,325 Pa ║ ║ Pascal's Principle: Hydraulic press ║ ║ ║ ║ WEEK 3: DENSITY & RELATIVE DENSITY ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ ρ = m/V, R.D. = ρ_substance / ρ_water ║ ║ Density of water = 1000 kg/m³ ║ ║ ║ ║ WEEK 4: TEMPERATURE & THERMOMETERS ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ °F = (°C × 9/5) + 32, K = °C + 273.15 ║ ║ Mercury: high boiling point, Alcohol: low freezing point ║ ║ ║ ║ WEEK 5: THERMAL EXPANSION ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ ΔL = αL₀ΔT, β ≈ 2α, γ ≈ 3α ║ ║ Anomalous expansion of water: max density at 4°C ║ ║ ║ ║ WEEK 6: THERMAL CONDUCTIVITY ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ Q/t = kAΔT/L, Good conductors: metals, Insulators: wood, rubber ║ ║ ║ ║ WEEK 7: LATENT HEAT ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ L_f = Q/m (fusion), L_v = Q/m (vaporization) ║ ║ Water: L_f = 3.34 × 10⁵ J/kg, L_v = 2.26 × 10⁶ J/kg ║ ║ ║ ║ WEEK 8: GAS LAWS ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ Boyle: P₁V₁ = P₂V₂, Charles: V₁/T₁ = V₂/T₂ ║ ║ Pressure: P₁/T₁ = P₂/T₂, Combined: P₁V₁/T₁ = P₂V₂/T₂ ║ ║ PV = nRT, Temperature must be in KELVIN ║ ║ ║ ║ WEEK 9: LIGHT – REFLECTION ║ ║ ───────────────────────────────────────────────────────────────────────── ║ ║ Laws: i = r, Specular vs Diffuse reflection ║ ║ Plane mirror: Virtual, upright, same size, laterally inverted ║ ║ Real image: can be projected, Virtual image: cannot be projected ║ ║ ║ ╚════════════════════════════════════════════════════════════════════════════╝