Module 2.1 - Physical Quantites, Units and Measurements

Question 1

Prefix - T

Answer 1

Tera - x10^12

Question 2

Prefix - G

Answer 2

Giga - x10^9

Question 3

Prefix - M

Answer 3

Mega - x10^6

Question 4

Prefix - K

Answer 4

Kilo - x10^3

Question 5

Prefix - m

Answer 5

Milli - x10^-3

Question 6

Prefix - µ

Answer 6

Micro - x10^-6

Question 7

Prefix - n

Answer 7

Nano - x10^-9

Question 8

Prefix - p

Answer 8

Pico - x10^-12

Question 9

Prefix - d

Answer 9

Deci - x10^-1

Question 10

Prefix - c

Answer 10

Centi - x10^-2

Question 11

56µm?

Answer 11

= 56 x 10^-6 m

= 5.6 x 10^-5 m

Question 12

3.2 x 10^10 Pa?

Answer 12

= 32 x 10^9 Pa

= 32 GPa

Question 13

195 ns to ms?

Answer 13

= 195 x 10^-9 s

= 0.000195ms

Question 14

SI unit for Acceleration?

Answer 14

ms^-2

Question 15

SI unit for Density?

Answer 15

kg m^-3

Question 16

SI unit for charge?

Answer 16

Coulombs - C

Question 17

SI unit for Energy?

Answer 17

Joules - J

Question 18

SI unit for Force?

Answer 18

N

Question 19

SI unit for Momentum?

Answer 19

kg ms^-1

Question 20

SI unit for p.d.?

Answer 20

V - Volts

Question 21

SI unit for Power?

Answer 21

W - Watts

Question 22

SI unit for Pressure?

Answer 22

Pascals - Pa

Question 23

SI unit for Velocity?

Answer 23

ms^-1

Question 24

What 3 things cause random errors?

Answer 24

> Small changes in the environment
Reading or recording values wrong
Unknown/Unpredictable changes to the experiment

Question 25

Example of random error?

Answer 25

Heating in circuits causing variations in current

Question 26

What 2 things cause systematic error?

Answer 26

> Faulty measuring instrument | > Instrument used incorrectly

Question 27

Examples of systematic error?

Answer 27

> Scale wrong on instrument | > Parallax error - not eye level when reading

Question 28

Define Accuracy

Answer 28

How close to the accepted/true value it is

Question 29

Define Precision

Answer 29

How close together repeat values are

Question 30

What is the absolute uncertainty?

Answer 30

The smallest division on an instrument

Question 31

How do you work out percentage uncertainty?

Answer 31

(Uncertainty ÷ Measured value) x 100