O-Level Combined Science (Phy/Chem) Topical Practice Questions & Answers

Practise O-Level Combined Science (Phy/Chem) multiple-choice questions aligned to the Singapore-Cambridge GCE O-Level examination. WeloScholars covers all 32 topics — including Physics: Measurement, Physics: Newtonian Mechanics, Physics: Thermal Physics, Physics: Waves — with curriculum-aligned MCQs, an AI tutor that explains every concept step by step, and analytics that show exactly where to focus next. Every question includes a clear explanation of the correct answer and why each distractor is wrong, building real conceptual understanding. Start free: no credit card needed, and your first practice session takes under a minute to set up.

All 32 O-Level Combined Science (Phy/Chem) topics

• Physical Quantities, Units and Measurement
  Recall the SI base units for mass, length, time, temperature, electric current and amount of substance.

• Kinematics
  Define and distinguish between distance and displacement, speed and velocity, and acceleration.
• Dynamics
  State Newton's First Law of Motion and apply it to explain inertia and equilibrium.
• Mass, Weight and Density
  Define mass and state its SI unit.
• Turning Effect of Forces
  Define the moment of a force (torque) and state its S.I. unit.
• Pressure
  Define pressure as force per unit area.
• Energy, Work and Power
  State the principle of conservation of energy.

• Kinetic Model of Matter
  Describe the arrangement, movement, and forces between particles in solids, liquids, and gases.
• Transfer of Thermal Energy
  Describe thermal energy transfer by conduction, convection, and radiation.
• Thermal Properties of Matter
  Distinguish between heat and temperature, and describe internal energy as the sum of random kinetic and potential energies of m…

• General Wave Properties
  Describe a wave as a phenomenon in which energy is transferred from one point to another without the transfer of matter.
• Light
  State the laws of reflection and apply them to plane mirrors.
• Electromagnetic Spectrum
  Describe the nature of electromagnetic waves as transverse waves that do not require a medium for propagation.
• Sound
  Describe sound as a form of energy transmitted through a medium as a longitudinal wave.

• Static Electricity
  Describe the production of electrostatic charges by friction and explain the concept of electrostatic induction.
• Current Electricity
  Define electric current as the rate of flow of charge and state its unit (ampere).
• D.C. Circuits
  Define electric current, potential difference, resistance, electromotive force (e.m.f.) and internal resistance.
• Magnetism
  Describe the properties of magnets and magnetic materials, including attraction and repulsion between poles.
• Electromagnetism
  Describe the magnetic effect of an electric current.
• Electromagnetic Induction
  Describe the phenomenon of electromagnetic induction.

• Experimental Chemistry
  Describe and explain the use of common laboratory apparatus and techniques for the separation and purification of substances (e…
• The Particulate Nature of Matter
  Describe the three states of matter (solid, liquid, gas) in terms of the arrangement, movement, and energy of their particles.
• Atomic Structure
  State the structure of an atom in terms of a central nucleus and extranuclear electrons.
• Chemical Bonding and Structure
  Describe the formation of ionic bonds between metallic and non-metallic elements through the transfer of electrons, leading to…
• Chemical Calculations
  Define and calculate relative atomic mass (Ar) and relative molecular mass (Mr).
• Acids, Bases and Salts
  Define acids, bases, and alkalis in terms of their properties and reactions.
• Redox Reactions
  Define oxidation and reduction in terms of oxygen gain/loss and hydrogen gain/loss.

• Energy from Chemical Reactions
  Define exothermic and endothermic reactions, and describe the energy changes (heat released or absorbed) associated with them.
• The Chemistry of the Atmosphere
  State the composition of clean air (nitrogen, oxygen, argon, carbon dioxide, water vapour) and their approximate percentages.
• The Periodic Table
  State that elements are arranged in the Periodic Table in order of increasing proton number.
• Metals
  State the general physical properties of metals (e.g., malleability, ductility, good conductors of heat and electricity, high m…

• Organic Chemistry
  Describe homologous series and functional groups.

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