LATEST OCR PHYSICS A LEVEL A-LEVEL BIOLOGY- OCR
ACTUAL EXAM QUESTIONS AND ANSWERS LATEST
UPDATED 2025 RATED A+ AND 100% GUARANTEE PASS
(BRAND NEW!!!!!!!)
What is impedance/acoustic matching? - CORRECT ANSWER-When two
substances havce similar acoustic impedances so negligible reflection of
ultrasound occurs.
What causes ulatrasound to undergo doppler shift? - CORRECT ANSWER-
Reflection from moving blood cells.
What is doppler ultrasound used for? - CORRECT ANSWERMeasuring the
speed (and volume) of blood flow.
What is measured in doppler ultrasound to determine the velocity of the blood?
- CORRECT ANSWER-The observed change in frequency of the reflected
ultrasound pulse.
What is a systematic error? - CORRECT ANSWER-An error that causes the
measurements to differ from the true value by a consistent amount.
What is 1m² in mm²? - CORRECT ANSWER-10⁶mm²
,What is 1m³ in cm³? - CORRECT ANSWER-10⁶cm³
What is 1km² in m²? - CORRECT ANSWER-1x10⁶m²
What is 1cm³ in mm³? - CORRECT ANSWER-10³mm³
There are 10²⁴ free charge carriers per m³ of a material. How many are there per
mm³? - CORRECT ANSWER-10¹⁵
10⁶ particles strike each mm² of a surface per second. How many strike
1m² of the surface per second? - CORRECT ANSWER-10¹²
If there is 1 particle per mm³, how many are there per m³? - CORRECT
ANSWER-10⁹
Water has a density of 1000kgm⁻³. What is this in kgcm⁻³? - CORRECT
ANSWER-10⁻³
Water has a density of 1000kgm⁻³. What is this in gcm⁻³? - CORRECT
ANSWER-1
What is a control variable? - CORRECT ANSWER-Something that must be kept
constant to prevent it affecting the dependent variable
,What is a zero error? - CORRECT ANSWER-An error that occurs due to the
measuring instrument reading a non-zero reading when the measured
quantity is zero.
What is meant by the accuracy of a result? - CORRECT ANSWER-How close a
measurement is to the 'true' or accepted value
What is meant by the precision of results? - CORRECT ANSWER-How close
repeated measurements are to each other.
What is meant by the resolution of a measuring instrument? - CORRECT
ANSWER-The smallest change in quantity that can be measured.
What determines the resolution when using a multimeter? - CORRECT
ANSWER-The scale selected.
What is the resolution of a metre rule? - CORRECT ANSWER-1mm
What is the resolution of vernier calipers? - CORRECT ANSWER-
0.1mm
What is the resolution of a micrometer - CORRECT ANSWER-0.01mm How do
you find the absolute uncertainty from repeated readings? - CORRECT
ANSWER-± ½ the range of the repeats
How do you estimate uncertainty when repeated results are identical? -
CORRECT ANSWER-± ½ the resolution of the instrument
, How do you calculate percentage uncertainty? - CORRECT ANSWER(Absolute
uncertainty ÷ 'calculated OR measured' value)
× 100
What do you do to the uncertainties when quantities are added or subtracted? -
CORRECT ANSWER-The absolute uncertainties are added together
What do you do to the uncertainties when quantities are multiplied or divided?
- CORRECT ANSWER-The percentage uncertainties are added together
What do you do to the uncertainties when a quantity is raised to a power? -
CORRECT ANSWER-The percentage uncertainty is multiplied by that power
How do you find the uncertainty in a gradient? - CORRECT ANSWER±
(gradient of the line of best fit − gradient of the line of worst fit)
What is a line of worst fit? - CORRECT ANSWER-The steepest or shallowest line
that passes through the error bars.
What are error bars? - CORRECT ANSWER-Lines to show the range of the
absolute uncertainty of each data point on a graph
ACTUAL EXAM QUESTIONS AND ANSWERS LATEST
UPDATED 2025 RATED A+ AND 100% GUARANTEE PASS
(BRAND NEW!!!!!!!)
What is impedance/acoustic matching? - CORRECT ANSWER-When two
substances havce similar acoustic impedances so negligible reflection of
ultrasound occurs.
What causes ulatrasound to undergo doppler shift? - CORRECT ANSWER-
Reflection from moving blood cells.
What is doppler ultrasound used for? - CORRECT ANSWERMeasuring the
speed (and volume) of blood flow.
What is measured in doppler ultrasound to determine the velocity of the blood?
- CORRECT ANSWER-The observed change in frequency of the reflected
ultrasound pulse.
What is a systematic error? - CORRECT ANSWER-An error that causes the
measurements to differ from the true value by a consistent amount.
What is 1m² in mm²? - CORRECT ANSWER-10⁶mm²
,What is 1m³ in cm³? - CORRECT ANSWER-10⁶cm³
What is 1km² in m²? - CORRECT ANSWER-1x10⁶m²
What is 1cm³ in mm³? - CORRECT ANSWER-10³mm³
There are 10²⁴ free charge carriers per m³ of a material. How many are there per
mm³? - CORRECT ANSWER-10¹⁵
10⁶ particles strike each mm² of a surface per second. How many strike
1m² of the surface per second? - CORRECT ANSWER-10¹²
If there is 1 particle per mm³, how many are there per m³? - CORRECT
ANSWER-10⁹
Water has a density of 1000kgm⁻³. What is this in kgcm⁻³? - CORRECT
ANSWER-10⁻³
Water has a density of 1000kgm⁻³. What is this in gcm⁻³? - CORRECT
ANSWER-1
What is a control variable? - CORRECT ANSWER-Something that must be kept
constant to prevent it affecting the dependent variable
,What is a zero error? - CORRECT ANSWER-An error that occurs due to the
measuring instrument reading a non-zero reading when the measured
quantity is zero.
What is meant by the accuracy of a result? - CORRECT ANSWER-How close a
measurement is to the 'true' or accepted value
What is meant by the precision of results? - CORRECT ANSWER-How close
repeated measurements are to each other.
What is meant by the resolution of a measuring instrument? - CORRECT
ANSWER-The smallest change in quantity that can be measured.
What determines the resolution when using a multimeter? - CORRECT
ANSWER-The scale selected.
What is the resolution of a metre rule? - CORRECT ANSWER-1mm
What is the resolution of vernier calipers? - CORRECT ANSWER-
0.1mm
What is the resolution of a micrometer - CORRECT ANSWER-0.01mm How do
you find the absolute uncertainty from repeated readings? - CORRECT
ANSWER-± ½ the range of the repeats
How do you estimate uncertainty when repeated results are identical? -
CORRECT ANSWER-± ½ the resolution of the instrument
, How do you calculate percentage uncertainty? - CORRECT ANSWER(Absolute
uncertainty ÷ 'calculated OR measured' value)
× 100
What do you do to the uncertainties when quantities are added or subtracted? -
CORRECT ANSWER-The absolute uncertainties are added together
What do you do to the uncertainties when quantities are multiplied or divided?
- CORRECT ANSWER-The percentage uncertainties are added together
What do you do to the uncertainties when a quantity is raised to a power? -
CORRECT ANSWER-The percentage uncertainty is multiplied by that power
How do you find the uncertainty in a gradient? - CORRECT ANSWER±
(gradient of the line of best fit − gradient of the line of worst fit)
What is a line of worst fit? - CORRECT ANSWER-The steepest or shallowest line
that passes through the error bars.
What are error bars? - CORRECT ANSWER-Lines to show the range of the
absolute uncertainty of each data point on a graph
