Practical Skills Flashcards
What are the S.I. base units?
Kg, m, s, A, k, mol, cd
What are the prefixes before a unit? State letter and number
f (10^-15), p (10^-12), n (10^-9), μ (10^-6), m (10^-3), c (10^-2), k (10^3), M (10^6), G (10^9), T (10^12)
What is a random error and how do you minimise it?
A random error is where measurements vary unpredictably. Minimise a random error by repeating the experiment and using an average measurement.
What is a systematic error and how does it affect a graph?
A systematic error is when the measurement values vary from the true values by the same amount each time. The graph will have the same gradient but a different y intercept.
What is the equation for percentage uncertainty?
(Absolute uncertainty / measured value) x 100
What does it mean if a value is accurate?
It is close to the accepted value.
What does it mean if a set of results are precise?
The results are similar to one another.
What does it mean if an experiment is reliable?
It gives consistent results.
What does resolution mean?
The smallest division on a measuring instrument.
What is the equation for percentage difference?
((Measured value - true value) / true value) x 100
