Measurements & their Errors Flashcards
How do we find uncertainty on measuring equipment
Lowest measurement division +-
How do we calculate percentage uncertainty
Uncertainty/measurement x 100
How do we calculate fractional uncertainty
Uncertainty/measurement
What is absolute uncertainty
The +- N
How do we find uncertainty in added/subtracted data
Add absolute uncertainties
How do we find uncertainty in multiplied/divided data
Add percentage uncertainties
How do we find uncertainty in data to a power
Multiply percentage uncertainty by the power
How do we draw a gradient with uncertainties
Draw a gradient going through all the error bars
How do we find uncertainty in a graph
Draw the steepest and shallowest gradients which both go through the error bars. Steepest - shallowest / steepest x 100
How do we reduce uncertainty
Take measurements of large quantities
Reproduce experiment
Precision
Define random error
An error from chance, can be caused b y slight fluctuations in the environment
Define systematic error
An error with a consist error in readings
Define human error
AN error caused by human fault or is something limited by their capabilities
Define zero error
An error when a measuring instrument stays at/can’t return to zero
How do you use a micrometer
Place item inside and screw it down
One revolution = 0.5mm
Fine devision = 0.001mm When the main divine lines up with the fine devision
How do you use a vernier calliper
Get smallest scale division and put object inside
Read number on main scale just before zero line
Read number on vernier scale
Final reading = main scale + vernier scale
What is the equation for least count
Least count = smallest scale division/number of divisions
Explain the different inputs you can do on a oscilloscope
Y gain: Determines sensitivity meaning it increase and decrease amplitudes to make it easier to read
Time base: How long it takes per unit measurement
X/Y shift can shift the wave in the X/Y axis
What is the conversion of 1 mile to kilometres
1 mile = 1.6km
Conversion of 1kg to pounds
1kg = 2.2 pounds
Name all prefixes of powers of 10 and their numbers
Tera - 12
Giga - 9
Mega - 6
Kilo - 3
Centi - -2
Milli - -3
Micro - -6
Nano - -9
Pico - -12
Femto - -15
