aqa a level physics paper 1
A particle that moves uniformly in a circular path is accelerating yet moving at a constant speed. Explain
this statement by reference to the physical principles involved (4) - correct answerspeed scalar velocity
vector (1) direction changes continuously (1) velocity changes (1) acceleration is rate of change of
velocity
Advantage of using a stranded cable rather than a solid cable of the same cross-sectional area - correct
answerlarger surface area so better heat dissipation
conditions for equilibrium - correct answerresultant force is 0 (1) resultant torque is 0 (1)
define center of gravity - correct answerthe point in a body (1) where the weight of an object appears to
act (1)
define center of mass - correct answerthe point in the body through which the mass appears to act
define density of a material - correct answermass per unit volume
define hookes law - correct answerExtension is proportional to the applied force up to limit of
proportionality (1)
as long as extension is small (1)
define moment of a force (2) - correct answerforce x perpendicular distance around a pivot (1) between
force and pivot (2)
define potential difference - correct answerwork done per unit charge
define yield stress of a material - correct answerforce per unit area (1) at which material permanently
deformed (1) for no/small increase in force
, definition of elastic limit - correct answermaximum force/load which can be applied to the object
without it being permanently deformed
describe what is meant by the period of an oscilation - correct answertime taken for one complete
oscillation
difference between scalar and vector - correct answervector has magnitude and direction scalar only has
magnitude
Effect on diffraction pattern when wavelength decreases (3) - correct answerMaxima closer together (1)
angle decreases (1) smaller path difference (1)
example of non-ohmic conductor - correct answerfilament lamp/LDR/thermistor
Explain how (bright ring) diagram is evidence of the wave-particle duality of electrons? - correct
answerDiffraction pattern maxima/minima (bright and dark areas) (1)
Diffraction is a property of waves- proves wave-behaviour of electrons (1)
Explain how excitation takes place in a fluorescent tube - correct answerElectrons flow through the tube
to the applied PD causing a current to flow (1)
Electrons collide with mercury atoms in the tube (1)
This raises electrons in the mercury atom to a higher energy level (1)
Explain the difference between excitation and ionisation (2) - correct answerAn electron receives a
discrete amount of energy for BOTH (1)
Excitation promotes an electron to a higher energy level
Ionisation is when an electron receives enough energy to leave the atom
explain what is meant by a potential divider - correct answera combination of resistors across a voltage
source to produce a required pd
A particle that moves uniformly in a circular path is accelerating yet moving at a constant speed. Explain
this statement by reference to the physical principles involved (4) - correct answerspeed scalar velocity
vector (1) direction changes continuously (1) velocity changes (1) acceleration is rate of change of
velocity
Advantage of using a stranded cable rather than a solid cable of the same cross-sectional area - correct
answerlarger surface area so better heat dissipation
conditions for equilibrium - correct answerresultant force is 0 (1) resultant torque is 0 (1)
define center of gravity - correct answerthe point in a body (1) where the weight of an object appears to
act (1)
define center of mass - correct answerthe point in the body through which the mass appears to act
define density of a material - correct answermass per unit volume
define hookes law - correct answerExtension is proportional to the applied force up to limit of
proportionality (1)
as long as extension is small (1)
define moment of a force (2) - correct answerforce x perpendicular distance around a pivot (1) between
force and pivot (2)
define potential difference - correct answerwork done per unit charge
define yield stress of a material - correct answerforce per unit area (1) at which material permanently
deformed (1) for no/small increase in force
, definition of elastic limit - correct answermaximum force/load which can be applied to the object
without it being permanently deformed
describe what is meant by the period of an oscilation - correct answertime taken for one complete
oscillation
difference between scalar and vector - correct answervector has magnitude and direction scalar only has
magnitude
Effect on diffraction pattern when wavelength decreases (3) - correct answerMaxima closer together (1)
angle decreases (1) smaller path difference (1)
example of non-ohmic conductor - correct answerfilament lamp/LDR/thermistor
Explain how (bright ring) diagram is evidence of the wave-particle duality of electrons? - correct
answerDiffraction pattern maxima/minima (bright and dark areas) (1)
Diffraction is a property of waves- proves wave-behaviour of electrons (1)
Explain how excitation takes place in a fluorescent tube - correct answerElectrons flow through the tube
to the applied PD causing a current to flow (1)
Electrons collide with mercury atoms in the tube (1)
This raises electrons in the mercury atom to a higher energy level (1)
Explain the difference between excitation and ionisation (2) - correct answerAn electron receives a
discrete amount of energy for BOTH (1)
Excitation promotes an electron to a higher energy level
Ionisation is when an electron receives enough energy to leave the atom
explain what is meant by a potential divider - correct answera combination of resistors across a voltage
source to produce a required pd
