standard questions Flashcards
How do you reduce % uncertainty when measuring
Use a longer measurement
How do you reduce uncertainty in measuring a liquid
Measure at eye level to the meniscus to reduce parallax error
What is systematic error
An error that occurs in every trial of the experiment due to equipment or something that is not adjusted
How can you reduce systematic error in an experiment
Ensure there is no zero error by calibrating all devices
Ensure the environment has no obstacle/interference to experiment
How do you reduce % uncertainty in general
Ensure there are control variable
How can you limit the effects of random error
Measure at different points
Calculate the average
discard anomalies
How do you work out the absolute uncertainty from the mean
It is half the range
How do you work out the % uncertainty?
absolute uncertainty/value * 100
When a question asks for the order of magnitude what do you give
10^?
only give what it is in the power of
log(s/m) on a graph what does the m indicate?
The unit of the the y variable which is meter
does using a point mass reduce uncertainty
yes
why is it important to use a voltmeter of high resistance
low current through it, so less charge is lost through the voltmeter
suggest an advantage of using an analogue ammeter rather than digital ammeter
Marking can be made on the scale which can be read off later unlike digital
What is a full scale deflection
It is the maximum value which the equipment is calibrated to
if you are asked to give the unit of the gradient and the change in y axis does not have a gradient what do you do?
Use only the change in x axis gradient
When you plot something against something what does that represent
plot a graph of y against x
what does the error bar show us
half of the absolute uncertainty up and down
when you have two lines to compare what must you find
the average
why would you repeat experiment and calculate the average
to reduce the impact of random error
why would you repeat readings to detect anomolies
so they can be discarded before averaging
why would you view at eye level
to remove parallax error
what is the SI unit of (n) and its prefix
Amount of substance; moles
what does random error effect
it effect precision by spreading the mean
what equipment can be used to reduce human error
data logger
