IGCSE Physics tutor: live classes, unit by unit

What the exam asks for

• Use motion equations and graph gradients to connect distance, time, speed and acceleration.
• Interpret force diagrams and explain how resultant force changes motion, including falling with resistance and terminal velocity.
• Apply conservation ideas to momentum, energy, work and power, showing numerical steps and units.
• Practise measurement, graphing and data handling for density, spring extension, motion and centre-of-gravity investigations.

Common slips to watch for

• Confusing distance with displacement, or speed with velocity, and omitting direction where it matters.
• Reading a graph’s height instead of its gradient for speed, or misidentifying a changing gradient as constant speed.
• Mixing mass and weight, using inconsistent units, or treating a negative acceleration as a negative speed.
• Forgetting that terminal velocity means balanced forces, or using the wrong distance or force in work and moment calculations.

What the exam asks for

• Explain changes of state and temperature using particle arrangement, motion and energy transfer.
• Apply gas relationships and temperature conversion with the stated constant conditions made explicit.
• Distinguish conduction, convection and radiation, linking each process to particle behaviour and suitable applications.
• Use practical descriptions and evidence to compare conductors and insulators, and interpret thermal observations.

Common slips to watch for

• Claiming temperature rises during melting or boiling instead of explaining where the supplied energy goes.
• Applying a gas relationship without checking which quantity is held constant.
• Describing convection in a solid, or treating radiation as requiring particles in a medium.
• Confusing particle expansion with increased separation or motion when explaining thermal expansion.

What the exam asks for

• Relate wave properties and representations to energy transfer without matter transfer.
• Use reflection and refraction diagrams with correctly measured angles from the normal.
• Construct converging-lens ray diagrams and connect focal length to image formation.
• Compare electromagnetic regions by order and uses, and describe sound as a longitudinal wave with a limited audible range.

Common slips to watch for

• Measuring angles from the mirror or surface instead of from the normal.
• Reversing the direction of refraction or drawing rays that do not pass through the appropriate focus.
• Confusing wavelength, amplitude and frequency, or claiming that a wave transports matter overall.
• Mixing electromagnetic spectrum order with the order of frequency or wavelength, or describing sound as transverse.

What the exam asks for

• Practise circuit diagrams and calculations involving charge, potential difference, emf, resistance, power and transferred energy.
• Compare series and parallel circuit behaviour, keeping current paths and source emf reasoning clear.
• Explain induction and motor effects through relative motion, magnetic fields, current direction and factors affecting the induced emf.
• Interpret field diagrams and practical evidence for magnetism, electrostatics, current-produced fields and transformers.

Common slips to watch for

• Confusing emf with potential difference, or omitting the meaning of work done per unit charge.
• Applying series rules to parallel branches, or assuming current is divided in a series circuit.
• Reversing field or current directions when explaining induction and motor effects.
• Confusing step-up with step-down transformers, or describing transmission voltage without linking it to transformer action.

What the exam asks for

• Explain atomic structure, ion formation and how alpha-scattering evidence supports a concentrated nucleus.
• Identify background radiation sources and describe how a detector and counter measure ionising radiation.
• Use decay tables and curves to find half-life, including data where background has not been removed.
• Connect radiation type and half-life with penetration, risk and appropriate safety precautions.

Common slips to watch for

• Saying that ions form when protons are gained or lost rather than electrons.
• Confusing the detector’s count rate with the source’s activity without considering background radiation.
• Reading the total count as source radiation when background is included, or miscounting the number of half-lives.
• Treating all radiation types as equally penetrating or assuming a longer half-life means faster decay.

What the exam asks for

• Connect Earth’s rotation and axial tilt with apparent solar motion, day and night, and seasonal changes.
• Explain lunar phases through the Moon’s orbit and the changing view of its illuminated portion.
• Use orbital radius and period to calculate or compare average orbital speed.
• Interpret descriptions and data about Solar System bodies and their orbits.

Common slips to watch for

• Explaining lunar phases as Earth’s shadow falling on the Moon rather than as a changing view of its lit half.
• Attributing seasons to Earth being nearer to or farther from the Sun instead of to axial tilt.
• Using diameter rather than orbital radius, or failing to use the period consistently when finding orbital speed.
• Confusing rotation with revolution when explaining daily motion and yearly changes.