Flashcards in Practical skills Deck (19)

Loading flashcards...

1

## When calculating an answer what is the appropriate number of significant figures to give your answer in?

### The same as the value with less number of significant figures.

2

## State the resolution of vernier callipers

### 0.1 mm

3

## State the resolution of a micrometer

### 0.01 mm

4

## Define repeatable

### When the person carrying out the experiment obtains similar results

5

## Define reproducible

### When another group carry out the experiment and obtain a similar pattern in their results

6

## Define resolution

### The smallest change an instrument can detect or display

7

## Define accurate results

### When the measured quantity has a value close to the true value

8

## Define precision

### When repeat readings have a small spread in the data

9

## Define uncertainty

### How accurately you can take a measurement or an expression of the spread of values taken.

10

## How can you find the uncertainty in a single measurement

### Your estimate using the precision of the equipment as a guide

11

## When an equation has addition or subtraction can you add the uncertainty or percentage uncertainty?

### uncertainty

12

## When an equation has multiplication or division can you add the uncertainty or percentage uncertainty?

### percentage uncertainty

13

## Define percentage uncertainty stating its equation

###
It is the percentage error in your measurements.

Percentage uncertainty = uncertainty / mean value (x100%)

14

## Explain how you can find the percentage uncertainty in a gradient

###
Find the gradient of the best line of fit.

Draw a worst case LOBT and find its gradient.

Calculate the percentage difference between the two values.

15

## Explain how you can find the percentage uncertainty in an intercept

###
Find the intercept from the best line of fit.

Draw a worst case LOBT and find its intercept.

Calculate the percentage difference between the two values.

16

## Define a reading

###
The value is found from a single judgment when using a piece of equipment.

e.g. thermometer, measuring cylinder.

the uncertainty is given as half the precision

17

## Define a measurement

### The value taken as the difference between the judgement between two values e.g. ruler. the uncertainty is given as half the precision x by 2

18

## Define random error

### Is an error that is different for every reading. This causes repeat readings to spread around the true value and scatter around the line of best fit affecting both the intercept and gradient.

19