measurements

Question 1

random error

Answer 1

an error which gives a scatter of readings about an average value. it has an equal chance of being positive of negative and can be reduced by averaging.

Question 2

systematic error

Answer 2

is a constant deviation of readings in one direction. all measurements will be too high or too low by a certain amount. it can be reduced by correct laboratory practice.

Question 3

precision (of a set of readings)

Answer 3

is the degree of closeness of the readings with one another. it is associated with small random error.

Question 4

precision (of an instrument)

Answer 4

is used to describe the level of uncertainty in an instrument’s scale. high precision instruments have small scale divisions.

Question 5

accuracy (of a set of readings)

Answer 5

the degree of closeness of the average value of the readings to the true value. it is associated with small systematic error.

Question 6

accuracy (of an instrument)

Answer 6

the closeness of a reading on an instrument to the true value of the quantity being measured. an accurate instrument will give readings close to the true values.

Question 7

vector quantity

Answer 7

has both magnitude and direction

Question 8

scalar quantity

Answer 8

has magnitude but no direction