standard questions

Question 1

How do you reduce % uncertainty when measuring

Answer 1

Use a longer measurement

Question 2

How do you reduce uncertainty in measuring a liquid

Answer 2

Measure at eye level to the meniscus to reduce parallax error

Question 3

What is systematic error

Answer 3

An error that occurs in every trial of the experiment due to equipment or something that is not adjusted

Question 4

How can you reduce systematic error in an experiment

Answer 4

Ensure there is no zero error by calibrating all devices

Ensure the environment has no obstacle/interference to experiment

Question 5

How do you reduce % uncertainty in general

Answer 5

Ensure there are control variable

Question 6

How can you limit the effects of random error

Answer 6

Measure at different points

Calculate the average

discard anomalies

Question 7

How do you work out the absolute uncertainty from the mean

Answer 7

It is half the range

Question 8

How do you work out the % uncertainty?

Answer 8

absolute uncertainty/value * 100

Question 9

When a question asks for the order of magnitude what do you give

Answer 9

10^?

only give what it is in the power of

Question 10

log(s/m) on a graph what does the m indicate?

Answer 10

The unit of the the y variable which is meter

Question 11

does using a point mass reduce uncertainty

Answer 11

yes

Question 12

why is it important to use a voltmeter of high resistance

Answer 12

low current through it, so less charge is lost through the voltmeter

Question 13

suggest an advantage of using an analogue ammeter rather than digital ammeter

Answer 13

Marking can be made on the scale which can be read off later unlike digital

Question 14

What is a full scale deflection

Answer 14

It is the maximum value which the equipment is calibrated to

Question 15

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?

Answer 15

Use only the change in x axis gradient

Question 16

When you plot something against something what does that represent

Answer 16

plot a graph of y against x

Question 17

what does the error bar show us

Answer 17

half of the absolute uncertainty up and down

Question 18

when you have two lines to compare what must you find

Answer 18

the average

Question 19

why would you repeat experiment and calculate the average

Answer 19

to reduce the impact of random error

Question 20

why would you repeat readings to detect anomolies

Answer 20

so they can be discarded before averaging

Question 21

why would you view at eye level

Answer 21

to remove parallax error

Question 22

what is the SI unit of (n) and its prefix

Answer 22

Amount of substance; moles

Question 23

what does random error effect

Answer 23

it effect precision by spreading the mean

Question 24

what equipment can be used to reduce human error

Answer 24

data logger

Question 25

What does systematic error effect

Answer 25

the accuracy

Question 26

How can you reduce systematic error

Answer 26

• ensure equipment is calibrated to remove zero error
• ensure the use of control variables

Question 27

How do you reduce fractional and percentage uncertainty

Answer 27

use larger quantities

Question 28

for digital readings how do you find the uncertainty

Answer 28

+- the last significant digit

Question 29

how do you identify uncertainty in a reading (e.g ruler)

Answer 29

half the smallest division

Question 30

How do you find the uncertainty for repeated data

Answer 30

half the range

Question 31

when adding or subtracting data how does this affect absolute uncertainties

Answer 31

you must add them

Question 32

when do you add percentage uncertainties

Answer 32

you multiply or divide data

Question 33

when do you multiply percentage uncertainty by the power

Answer 33

when raising then to powers

Question 34

what piece of equipment is used to reduce angle of parallax

Answer 34

a set square

Question 35

What is systematic error

Answer 35

error that is the same for every reading