12. Motion in a Circle
Radian (1)
9702_s25_qp_42-Q1.a
- Angle subtended at centre of circle when arc length is equal to radius of the circle
Centripetal Acceleration (1)
9702_w21_qp_42-Q1.a
- Acceleration perpendicular to velocity
13. Gravitational Fields
Field of Force (2)
9702_w17_qp_42-Q9.a
- Region of space where a particle experiences a force
Gravitational Field (1)
9702_w25_qp_41-Q3.a
- Force per unit mass
Gravitational Field Line (2)
9702_s25_qp_42-Q2.a.i
- Direction of force
- acting on a test mass
Gravitational Field Strength (1)
9702_w18_qp_42-Q1.a.i
- Force per unit mass
Newton's Law of gravitation (2)
9702_w25_qp_44-Q1.a
- Gravitational force between two point masses is directly proportional to the product of their masses
- and inversely proportional to the square of their separation
Features of geostationary orbit (3)
9702_m19_qp_42-Q4.a
- Orbit is above the equator
- Orbital period of 24 hours
- Orbits west to east
- One particular orbital radius
Gravitational Potential at a point (2)
9702_s25_qp_41-Q1.a
- Work done per unit mass
- in moving a small test mass from infinity to a point
14. Temperature
Thermal Equilibrium (2)
9702_s25_qp_44-Q2.a
- Same temperature as each other
- no net transfer of thermal energy between them
Absolute Zero (2)
9702_w11_qp_43-Q2.b.ii
- Temperature at which atoms have zero energy
- Equivalent to -273.15 degrees Celsius
Specific Heat Capacity (1)
9702_s25_qp_42-Q3.a
- Thermal energy per unit mass per unit change in temperature
Specific latent heat (2)
9702_s25_qp_41-Q3.a
- Thermal energy per unit mass to cause state change
- at constant temperature
Specific latent heat of fusion (2)
9702_w08_qp_4-Q2.a
- Thermal energy per unit mass
- to change state from solid to liquid at constant temperature
Specific latent heat of vaporisation (2)
9702_s22_qp_42-Q3.a
- Thermal energy per unit mass
- to change state from liquid to gas at constant temperature
15. Ideal Gases
Mole (2)
FROM CHEMISTRY!
- Amount of substance
- containing Avogadro’s number of particles
Avogadro's Constant (1)
9702_w24_qp_41-Q3.a.i
- Number of particles per unit amount of substance
16. Thermodynamics
Internal energy of ideal gas (2)
9702_w25_qp_44-Q3.a, 9702_m24_qp_42-Q2.a
- Total kinetic energy associated with the random motion of molecules
- plus total potential energy of molecules but potential energy is zero
Internal energy of a system (2)
9702_s25_qp_41-Q4.a.i
- Sum of potential energy and kinetic energy
- total energy of random motion of particles
First law of thermodynamics (2)
9702_w25_qp_42-Q4.a
- change in internal energy = work done + energy transfer by heating
- increase in internal energy = work done on system + energy transferred to the system by heating.
17. Oscillations
Simple harmonic motion (2)
9702_s25_qp_42-Q5.a
- Motion in which acceleration is directly proportional to displacement
- and acceleration is always in opposite direction to displacement.
Angular frequency (1)
9702_w17_qp_41-Q2.a
- Angular frequency =
Damping (2)
9702_w25_qp_42-Q5.b.i
- Loss of energy of oscillations
- due to resistive forces
Resonance (2)
9702_s22_qp_42-Q4.a
- Oscillations of object are at maximum amplitude
- when driving frequency equals natural frequency of object
Natural frequency (2)
9702_m18_qp_42-Q4.a
- Frequency at which a body will vibrate when there is no external force acting on it
18. Electric fields
Electric field (1)
9702_w25_qp_42-Q6.a
- force per unit positive charge
Electric field line (2)
9702_m22_qp_42-Q4.a
- Direction of force
- on a positive charge
Electric field strength (1)
9702_s19_qp_41-Q5.a
- Force per unit positive charge
Coulomb's law
9702_s25_qp_41-Q2.a
- Electric force between two point charges is directly proportional to the product of their charges
- and inversely proportional to the square of their separation
Electric potential (2)
9702_s24_qp_42-Q5.a
- Work done per unit charge
- in brining positive charge from infinity to a point
19. Capacitance
Capacitance of parallel plate capacitor (2)
9702_w24_qp_42-Q7.a
- Ratio of charge on one plate
- to potential difference between the plates
20. Magnetic fields
Magnetic field (1)
9702_m20_qp_42-Q8.a
- Region of space where a moving charge experiences a force
Magnetic flux density (2)
9702_s25_qp_41-Q7.a
- Force per unit length
- per unit current
- Where length and current are perpendicular to magnetic field
2 marks for all 3 points
Tesla (2)
9702_w21_qp_41-Q8.a
- Newton per ampere per metre
- where current is perpendicular to magnetic field
Magnetic Flux (2)
9702_m18_qp_42-Q10.a.i
- Product of magnetic flux density and area
- where direction of flux is normal to area
Magnetic flux linkage (2)
9702_m21_qp_42-Q9.a
- Product of magnetic flux density and area and number of turns
- where area is perpendicular to magnetic field
Faraday's law of electromagnetic induction (2)
9702_m25_qp_42-Q7.a
- Induced e.m.f. is directly proportional
- to rate of change of magnetic flux linkage
Induced e.m.f. not magnitude of induced e.m.f.
Lenz's law of electromagnetic induction (2)
9702_w25_qp_44-Q7.a
- Direction of induced e.m.f.
- is such as to produce effects that oppose the change that caused it
21. Alternating currents
Frequency of an alternating current (1)
9702_w24_qp_42-Q8.a
- Number of cycles per unit time
Root-mean-square value of an AC voltage (1)
9702_w21_qp_41-Q9.a
- Constant voltage
- that dissipates same power as the mean power of the alternating voltage
Rectification of an alternating voltage (1)
9702_w24_qp_41-Q6.a.i
- Conversion from AC to DC
Smoothing (1)
9702_w11_qp_43-Q5.c.i
- Reduction in the variation of the output voltage of a rectification circuit
22. Quantum Physics
Photon (2)
9702_w25_qp_41-Q8.a
- Quantum of energy
- of electromagnetic radiation
Photoelectric effect (2)
9702_s25_qp_42-Q9.a
- Emission of electrons from a metal surface
- when electromagnetic radiation is incident on the surface
Threshold frequency (2)
9702_m16_qp_42-Q11.a
- Minimum frequency of electromagnetic radiation needed
- for emission of electrons from a metal surface to occur
Work function energy (2)
9702_w22_qp_41-Q8.a
- Minimum photon energy
- to remove an electron from the surface of a metal
Wave particle duality (2)
9702_s25_qp_44-Q9.a.i
- Electromagnetic wave can behave like a particle
- moving particle can behave like a wave
de Broglie wavelength (1)
9702_s25_qp_41-Q8.a
- Wavelength associated with a moving particle
23. Nuclear physics
Mass defect of a nucleus (2)
9702_w25_qp_42-Q9.a
- Difference between mass of nucleus and mass of constituent nucleons
- when nucleons are separated to infinity
Nuclear binding energy (2)
9702_s24_qp_42-Q9.a
- Energy required to separate all the nucleons in the nucleus
- to infinity
Nuclear fusion (2)
9702_w23_qp_41-Q9.a
- Two small nuclei join together
- to form one large nucleus
Nuclear fission (2)
9702_w20_qp_42-Q12.a.ii
- A single large nucleus divides to form smaller nuclei
- total binding energy increases
Radioactive decay (3)
9702_w18_qp_41-Q12.a
- Spontaneous emission
- of particles or photons
- from an unstable nucleus
Random nature of radioactive decay (1)
9702_m25_qp_42-Q9.a
- Cannot predict when a particular nucleus will decay
Spontaneous nature of radioactive decay (1)
9702_m25_qp_42-Q9.a
- Not affected by external factors
Activity of a radioactive sample (1)
9702_w25_qp_44-Q8.c.i
- number of nuclear disintegrations per unit time
Decay constant (2)
9702_m18_qp_42-Q13.a.i
- probability of decay of a nucleus
- per unit time
Half life (1)
9702_m25_qp_42-Q9.b
- time for activity to halve
24. Medical Physics
Specific acoustic impedance (2)
9702_s25_qp_44-Q10.b.i
- Product of density of medium
- and speed of ultrasound in medium
Attenuation of ultrasound wave (2)
9702_w19_qp_42-Q5.c.i
- Reduction in intensity of wave
- as the wave passes through a medium
Sharpness of an X-ray image (1)
9702_w15_qp_41-Q10.a
- Clarity of edges of image
Contrast of an X-ray image (1)
9702_w15_qp_41-Q10.a
- difference in degree of blackening of structures
Hardness of an X-ray beam (1)
9702_m16_qp_42-Q12.a.i
- The penetration of the beam
Tracer (2)
9702_w25_qp_44-Q8.a
- Radioactive substance introduced into the body
- which is absorbed by the tissues being studied
Annihilation (1)
9702_m22_qp_42-Q11.b.i
- A particle interacting with its antiparticle so that the mass is converted into energy
25. Astronomy and cosmology
Luminosity of a star (1)
9702_m25_qp_42-Q10.a.i
- total power of radiation emitted by the star
Standard candle (1)
9702_m23_qp_42-Q10.b
- Object with known luminosity
Wien's displacement law (2)
9702_w25_qp_41-Q9.a
- Temperature is inversely proportional to wavelength
- Where temperature is thermodynamic temperature of surface of star
- and wavelength is the wavelength at which maximum emission rate from star occurs
2 marks for all 3 points
Redshift (2)
9702_w25_qp_44-Q10.a
- Recession of galaxy from observer causes emitted light to have
- increase in observed wavelength
Hubble's Law (2)
9702_s25_qp_41-Q10.a
- Speed is directly proportional to distance
- where speed is speed of recession of galaxy from observer
- and distance is the distance of the galaxy from the observer
2 marks for 3 points