AQA A Level Physics Paper 3 Section A Questions And Answers
2025/2026
What is a set square used for? (5 uses) - CORRECT ANSWER-A set square is a right-
angled triangle used to:
- Determine whether an object is vertical,
- Determine whether two objects are at right angles to each other,
- Determine whether two lines are parallel,
- Measure the diameter of a circular cross-section (using 2 set squares and a
ruler),
- Make sure your eyes are level (reducing parallax error).
NB: similar to a set square, a plumb line or spirit level can be used to test the
alignment of an experimental setup.
Explain a procedure to accurately determine the time period of oscillation. -
CORRECT ANSWER-- Time over multiple oscillations (at least 10) using a stop
clock.
- Find the mean time period.
- Place a fiducial marker at the centre of oscillation. The mass moves past this
point at the greatest speed so there is the least uncertainty in starting and
stopping the stop clock (reducing random errors due to human reaction time).
, - Make sure the amplitude of oscillation is large so that the time period is greater
(hence reducing uncertainty). The initial effect of damping will also be reduced.
- Make sure the system oscillates in one plane.
Describe how a mirror can be used to reduce parallax error. - CORRECT ANSWER-
A mirror can be used to minimise parallax error when determining where a pin
lines up with a scale. This is done by lining up the pin with its own reflection and
then taking a measurement. This is particularly useful when reading analogue
meters.
Outline two procedures a student could use to make accurate measurements of
the amplitude of oscillations of either a mass-spring system or a pendulum. -
CORRECT ANSWER-Mass spring
- Select large initial amplitude to reduce % uncertainty in subsequent values but
care needed that the masses don't fall off the mass holder.
- Select suitable equipment for measurement of amplitude such as a data logger
connected to a computer with a distance sensor positioned underneath the tray
or a means of capturing a film or video of the oscillating tray and masses which
includes a scale or ruler to allow determination of amplitude values.
- Use a large value for mass to increase the time period and hence reduce the %
uncertainty in time measurement.
From A level MS (for a pendulum):
Use a horizontal scale (e.g. ruler).
2025/2026
What is a set square used for? (5 uses) - CORRECT ANSWER-A set square is a right-
angled triangle used to:
- Determine whether an object is vertical,
- Determine whether two objects are at right angles to each other,
- Determine whether two lines are parallel,
- Measure the diameter of a circular cross-section (using 2 set squares and a
ruler),
- Make sure your eyes are level (reducing parallax error).
NB: similar to a set square, a plumb line or spirit level can be used to test the
alignment of an experimental setup.
Explain a procedure to accurately determine the time period of oscillation. -
CORRECT ANSWER-- Time over multiple oscillations (at least 10) using a stop
clock.
- Find the mean time period.
- Place a fiducial marker at the centre of oscillation. The mass moves past this
point at the greatest speed so there is the least uncertainty in starting and
stopping the stop clock (reducing random errors due to human reaction time).
, - Make sure the amplitude of oscillation is large so that the time period is greater
(hence reducing uncertainty). The initial effect of damping will also be reduced.
- Make sure the system oscillates in one plane.
Describe how a mirror can be used to reduce parallax error. - CORRECT ANSWER-
A mirror can be used to minimise parallax error when determining where a pin
lines up with a scale. This is done by lining up the pin with its own reflection and
then taking a measurement. This is particularly useful when reading analogue
meters.
Outline two procedures a student could use to make accurate measurements of
the amplitude of oscillations of either a mass-spring system or a pendulum. -
CORRECT ANSWER-Mass spring
- Select large initial amplitude to reduce % uncertainty in subsequent values but
care needed that the masses don't fall off the mass holder.
- Select suitable equipment for measurement of amplitude such as a data logger
connected to a computer with a distance sensor positioned underneath the tray
or a means of capturing a film or video of the oscillating tray and masses which
includes a scale or ruler to allow determination of amplitude values.
- Use a large value for mass to increase the time period and hence reduce the %
uncertainty in time measurement.
From A level MS (for a pendulum):
Use a horizontal scale (e.g. ruler).
