Edexcel A-Level Physics sample questions and answers (9PH0)
Guide overview All 13 topics Sample questions Papers and weighting Look inside Questions and answers
65 sample questions and answers
Taken from every topic of Edexcel A-Level Physics, specification 9PH0. The full guide has 1,616.
Paper 1, Paper 2, Paper 3
Working as a Physicist
82 questions in the guide, across 7 subtopics. More from this topic
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SI base units, derived units and homogeneity
What is the newton expressed in SI base units?
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Since force is mass times acceleration, 1 N = 1 kg m s⁻². -
SI base units, derived units and homogeneity
The spring constant k is force divided by extension, so what are its SI base units?
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Its unit is N m⁻¹, which in base units is kg s⁻². -
Unit prefixes, conversion and order-of-magnitude estimates
Why should the result of an estimate normally be quoted to one significant figure?
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The input values are only roughly known, so further figures would imply a precision the estimate does not have. -
Unit prefixes, conversion and order-of-magnitude estimates
What does the symbol ∝ mean in a relationship such as F ∝ Δp/Δt?
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It means 'is directly proportional to', so doubling the rate of change of momentum doubles the force; the relationship becomes an equation F = kΔp/Δt, and in SI units k = 1. -
Resolution, random errors and systematic errors
How can the effect of random error on a result be reduced?
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Repeat the measurement several times and take the mean, since random deviations above and below the true value tend to cancel.
Paper 1, Paper 3
Mechanics
180 questions in the guide, across 17 subtopics. More from this topic
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The equations of uniformly accelerated motion
Why does s = (u + v)t/2 follow from the definition of average velocity when the acceleration is uniform?
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For constant acceleration the average velocity is the mean of the initial and final velocities, and displacement is average velocity multiplied by time. -
Scalars and vectors
What are four examples of scalar quantities met in mechanics?
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Mass, energy, speed and time are all scalars. -
Projectile motion
What quantity links the horizontal and vertical motions of a projectile?
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The time, which is the same for both motions. -
Newton's third law, mass and weight
A ball falls towards the Earth. What is the Newton's third law partner of the Earth's gravitational pull on the ball?
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It is the equal and opposite gravitational pull of the ball on the Earth. -
Linear momentum and its conservation
How does conservation of momentum follow from Newton's third law of motion?
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The two interacting bodies exert equal and opposite forces on each other for the same length of time, so they experience equal and opposite changes of momentum which cancel.
Paper 1, Paper 3
Electric Circuits
148 questions in the guide, across 14 subtopics. More from this topic
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Current, charge and potential difference
Which charged particles carry the current in a metal wire?
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The free (delocalised) conduction electrons. -
Resistance, Ohm's law and ohmic behaviour
State the equation for the power dissipated in a component in terms of potential difference and current:
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P = VI, where P is the power in watts. -
Kirchhoff's laws: the current and potential difference rules
Which conservation law explains how the potential differences are shared around a circuit loop?
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Conservation of energy, since each coulomb must deliver all the energy it gained from the source by the time it returns to it. -
Combining resistances in series and parallel
Two identical resistors of resistance R are connected in parallel. What is their combined resistance?
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The combined resistance is R/2. -
I-V characteristics of conductors, lamps and diodes
Why does the characteristic curve of a filament lamp bend over as the current increases?
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The larger current heats the filament, and the resistance of the metal rises with temperature, so equal increases in potential difference produce progressively smaller increases in current.
Paper 2, Paper 3
Materials
101 questions in the guide, across 12 subtopics. More from this topic
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Density and how it is measured
A density is quoted as 1 g cm⁻³. What is this in SI units?
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It is 1 × 10³ kg m⁻³. -
Upthrust and Archimedes' principle
Under what condition does an object float in a fluid?
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It floats when it can displace fluid whose weight equals its own weight, which happens when its average density is less than the density of the fluid. -
Viscosity, laminar flow and Stokes' law
What is the SI unit of viscosity?
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Viscosity is measured in pascal seconds, Pa s, which is the same as N s m⁻². -
Terminal velocity of a sphere falling through a liquid
Two ball bearings of the same material are dropped into the same oil, one having twice the radius of the other. What is the ratio of their terminal velocities?
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Since terminal velocity is proportional to r², the larger ball reaches four times the terminal velocity of the smaller one. -
Hooke's law, stress and strain
What does a large value of k tell you about a spring?
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The spring is stiff, so a large force is needed to produce a given extension.
Paper 2, Paper 3
Waves and Particle Nature of Light
288 questions in the guide, across 29 subtopics. More from this topic
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Describing a progressive wave
What is meant by the wavelength of a wave?
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The wavelength is the shortest distance between two points on the wave that are oscillating in phase, such as one crest and the next. -
Displacement-distance and displacement-time graphs
How is a node identified on a displacement graph of a stationary wave?
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A node is a position where the displacement is permanently zero, so every trace of the wave crosses the axis at that same point. -
Interference in practice
Why does walking along a line in front of two loudspeakers emitting the same note produce alternating loud and quiet regions?
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The two distances to the listener change at different rates, so the path difference cycles through whole and half-integer numbers of wavelengths, giving alternate constructive and destructive interference. -
Investigating a vibrating string, and air columns
How can the uncertainty in locating the resonant frequency be reduced?
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Approach the resonance from above and below, note the range of frequencies over which the loop amplitude is largest, and take the mid-point of that range as the resonant frequency. -
Lenses, ray diagrams and the images they form
How is a ray arriving parallel to the axis of a diverging lens refracted?
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It emerges travelling as though it had come from the principal focus on the same side of the lens as the object.
Paper 1, Paper 3
Further Mechanics
98 questions in the guide, across 10 subtopics. More from this topic
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Impulse and force-time graphs
What is meant by the impulse of a force?
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Impulse is the product of a force and the time for which it acts, FΔt, and it equals the change of momentum it produces. -
Conservation of momentum in two dimensions
How does conservation of momentum follow from Newton's third law?
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Two interacting bodies exert equal and opposite forces on each other for the same length of time, so they receive equal and opposite impulses and their momentum changes cancel exactly. -
Investigating momentum and analysing collisions on video
In the core practical linking force to change of momentum, what systematic error affects the results, and how can it be reduced?
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Friction in the wheels and pulley makes the measured momentum change too small; it is reduced by tilting the runway slightly so the trolley moves at constant velocity when given a gentle push. -
Elastic and inelastic collisions
What calculation do you carry out to decide whether a collision is elastic or inelastic?
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Work out the total kinetic energy of all the bodies before the collision and again afterwards; if the two totals are equal the collision is elastic, and if the total falls it is inelastic. -
Kinetic energy, momentum and collision calculations
An electron of mass 9.11 × 10⁻³¹ kg has a momentum of 2.0 × 10⁻²⁴ kg m s⁻¹. What is its kinetic energy?
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Using Eₖ = p²/(2m), Eₖ = (2.0 × 10⁻²⁴)² ÷ (2 × 9.11 × 10⁻³¹) = 2.2 × 10⁻¹⁸ J.
Paper 1, Paper 3
Electric and Magnetic Fields
187 questions in the guide, across 19 subtopics. More from this topic
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Electric fields and electric field strength
How is electric field strength defined?
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It is the force per unit positive charge acting on a small charge placed at that point in the field. -
Coulomb's law and the field of a point charge
What is the value of the combination 1/(4πε₀)?
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It is approximately 8.99 × 10⁹ N m² C⁻². -
Electric potential and field strength as a potential gradient
Why does a minus sign appear in the relation between field strength and potential gradient?
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Because the field acts in the direction in which potential decreases. -
Equipotentials, field diagrams and work done
What do the equipotentials in the uniform field between two parallel plates look like?
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They are straight lines parallel to the plates and equally spaced for equal steps in potential. -
Capacitor charge and energy calculations
A 100 μF capacitor holds a charge of 6.0 mC. How much energy is stored?
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W = Q²/(2C) = (6.0 × 10⁻³)² ÷ (2 × 100 × 10⁻⁶) = 0.18 J.
Paper 1, Paper 3
Nuclear and Particle Physics
120 questions in the guide, across 11 subtopics. More from this topic
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Nuclide notation, isotopes and the alpha scattering experiment
How are the two numbers written when a nuclide is represented in symbol form?
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The nucleon number is written as a superscript to the left of the chemical symbol and the proton number as a subscript below it. -
Conclusions from alpha scattering and the changing model of the atom
Which force is responsible for deflecting the alpha particles?
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The electrostatic repulsion between the positively charged alpha particle and the positively charged nucleus. -
Thermionic emission and linear accelerators
How much kinetic energy does an electron gain when accelerated from rest through a potential difference V?
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It gains energy eV, so for a non-relativistic electron ½mv² = eV. -
The cyclotron and the radius of a charged particle's path
Why does a particle in a cyclotron spiral outwards?
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Its momentum increases each time it crosses the gap, and since r = p/(BQ) with B and Q fixed, each successive semicircle has a larger radius. -
Particle tracks, conservation laws and why high energies are needed
Why does an uncharged particle leave no track in a detector?
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It does not ionise the material it passes through, so its presence must be deduced from the tracks of charged particles produced when it decays or interacts.
Paper 2, Paper 3
Thermodynamics
96 questions in the guide, across 10 subtopics. More from this topic
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Specific heat capacity and specific latent heat
What is meant by the specific latent heat of a substance?
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It is the energy needed to change the state of 1 kg of the substance without any change in temperature. -
Measuring specific heat capacity and calibrating a thermistor
What two steps would reduce heat losses when measuring a specific heat capacity?
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Lag the block or container with insulation, and keep the temperature rise small so the sample spends less time above room temperature. -
Measuring specific latent heat
How can the specific latent heat of fusion of ice be found using an electrical heater?
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Place an immersion heater of known power in a funnel packed with melting ice, collect and weigh the melt water produced in a measured time, then use L = Pt/Δm. -
Internal energy, temperature and absolute zero
What happens to the internal energy of a solid as it melts at a constant temperature?
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The internal energy increases because the molecular potential energy rises as bonds are broken, while the mean molecular kinetic energy stays the same. -
Mean kinetic energy and the absolute temperature scale
A gas is heated from 27 °C to 327 °C. By what factor does the mean kinetic energy of its molecules increase?
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The absolute temperature rises from 300 K to 600 K, so the mean kinetic energy doubles.
Paper 2, Paper 3
Space
72 questions in the guide, across 7 subtopics. More from this topic
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Luminosity, intensity and the inverse square law
State the equation relating the intensity received from a star to its luminosity and distance:
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The equation is I = L/(4πd²), where d is the distance from the source. -
Luminosity, intensity and the inverse square law
A star of luminosity 3.9 × 10²⁶ W is 1.5 × 10¹¹ m away. What intensity is received?
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I = 3.9 × 10²⁶/(4π × (1.5 × 10¹¹)²) = 1.4 × 10³ W m⁻². -
Trigonometric parallax and standard candles
A star has a parallax angle of 0.25 arcseconds. How far away is it in parsecs and in metres?
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The distance is 1/0.25 = 4.0 pc, which is 4.0 × 3.09 × 10¹⁶ = 1.2 × 10¹⁷ m. -
Trigonometric parallax and standard candles
Why are standard candles needed when parallax already exists?
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Parallax angles become unmeasurably small beyond a few thousand parsecs, so standard candles are the only way to reach other galaxies. -
The Hertzsprung-Russell diagram
In what units is luminosity usually shown on a Hertzsprung-Russell diagram?
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It is usually given as a multiple of the Sun's luminosity.
Paper 2, Paper 3
Nuclear Radiation
82 questions in the guide, across 7 subtopics. More from this topic
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Mass deficit, binding energy and the atomic mass unit
State the equation linking a change in energy to the associated change in mass:
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ΔE = c²Δm, where c is the speed of light in a vacuum. -
Mass deficit, binding energy and the atomic mass unit
How much energy in joules is equivalent to a mass of 1 u?
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ΔE = 1.66 × 10⁻²⁷ × (3.00 × 10⁸)² = 1.49 × 10⁻¹⁰ J. -
Binding energy per nucleon, fission and fusion
What happens in nuclear fission?
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A heavy nucleus splits into two lighter nuclei of roughly comparable size, usually releasing two or three neutrons as well. -
Binding energy per nucleon, fission and fusion
Why can no energy be released by fusing nuclei heavier than iron?
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Beyond iron the binding energy per nucleon decreases, so the product would be less tightly bound and energy would have to be supplied rather than released. -
Background radiation and the three types of nuclear radiation
How would you obtain a reliable value for the background count rate?
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Record the counts over a long period with no source nearby and divide by the time to get a mean count rate.
Paper 2, Paper 3
Gravitational Fields
62 questions in the guide, across 6 subtopics. More from this topic
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Gravitational fields and gravitational field strength
State the defining equation for gravitational field strength and give its unit:
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g = F/m, measured in N kg⁻¹. -
Gravitational fields and gravitational field strength
What do the field lines look like in the region very close to the Earth's surface?
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They are parallel, equally spaced and directed vertically downwards, showing a uniform field. -
The field of a point mass and calculations with g
The Earth has a mass of 5.97 × 10²⁴ kg and a radius of 6.37 × 10⁶ m. What is g at its surface?
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g = 6.67 × 10⁻¹¹ × 5.97 × 10²⁴ ÷ (6.37 × 10⁶)² = 9.81 N kg⁻¹. -
The field of a point mass and calculations with g
Two masses lie some distance apart. What happens to the resultant field strength at a point on the line between them?
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The two fields point in opposite directions there, so they partly cancel, and at one particular point the resultant field strength is zero. -
Newton's law of universal gravitation
In the equation for universal gravitation, what exactly does r measure for two spherical bodies?
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It is the distance between their centres, not the gap between their surfaces.
Paper 2, Paper 3
Oscillations
100 questions in the guide, across 9 subtopics. More from this topic
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The conditions for simple harmonic motion
Why does a mass hanging on a spring perform simple harmonic motion when it is displaced vertically?
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An extra displacement x stretches the spring further, producing an extra force kx directed back towards equilibrium, which is exactly the condition F = −kx. -
Displacement, velocity and acceleration in simple harmonic motion
State the equation for the velocity of a simple harmonic oscillator released from maximum displacement:
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v = −Aω sin ωt. -
The mass-spring oscillator and the simple pendulum
State the equation for the period of a simple pendulum and the assumption it relies on:
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T = 2π√(l/g), valid provided the angular amplitude is small. -
Displacement, velocity and acceleration graphs
Where is the displacement–time graph steepest, and what does this tell you?
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It is steepest where it crosses the time axis, at the equilibrium position, showing that the oscillator is moving at its maximum speed there. -
Reading period, amplitude and speed from oscillation graphs
What does the area under a velocity–time graph for an oscillator represent?
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It represents the displacement of the oscillator over that time interval.
Edexcel A-Level Physics Active Recall Guide
The other 1,551 questions, with the answers printed after each section.