Physical Quantites & SI Units

Question 1

What are the 7 SI base quantities and units (MET-TALL) , also give their symbol and unit

Answer 1

Mass, m, Killogram (kg
Electric Current, I, ampere (A)
Time, t, second(s)
Temperature, T, Kelvin(k)
Amount of substance, n, mole (mol)
Luminous intensity, Iv, candela (cd)
Length, l, meter(m)

Question 2

What are the 1 derived base units (SPEED-FAMI) PAVVV

Answer 2

Speed, Pressure, Energy/work, Electric charge, Density, Force, Area, Momentum, Impulse
Power, Acceleration, Velocity, Voltage and Volume

Question 3

What is a homogeneous/dimensionally correct equation

Answer 3

An equation where the units/dimension on both sides are equal

Question 4

A scalar quantity has

Answer 4

Magnitude only

Question 5

A vector quantity has

Answer 5

Both magnitude and direction

Question 6

Examples of scalar quantities

Answer 6

time speed length distance temperature mass power energy density and pressure

Question 7

Examples of vector quantities

Answer 7

Weight, displacement, velocity, acceleration force, momentum, and electric field strength

Question 8

Scientific notation

Answer 8

A.bc x 10 ^ d where 1 ≤ A ≤ 9

Question 9

Precision is

Answer 9

How close a series of obtained measurements are to each other

Question 10

Accuracy is

Answer 10

How close the obtained value is to the accepted/actual/true value

Question 11

What is the precision of an instrument?

Answer 11

The smallest non-zero reading an instrument can measure or obtain

Question 12

What is the sensitivity of an instrument?

Answer 12

The ability of the instrument to detect and respond to the smallest changes in the quantity being measured.

Question 13

What is the range of an instrument?

Answer 13

The difference between the maximum and minimum value an instrument can measure

Question 14

Gradient equals

Answer 14

The difference of the Y values over the difference of the X values

Question 15

Straight line equation of a graph

Answer 15

y= mx + c
where m is the gradient and c is the why intercept if c=0 y and x are proportional

Question 16

Logs: 4^2 =16

Answer 16

log Base answer power
Log 16 to the base 4= 2

Question 17

F y aka vertical component =

Answer 17

Fsinθ
Y is sin

Question 18

Fx aka horizontal component equals

Answer 18

Fcosθ
X is cos

Question 19

θ in vectors equals

Answer 19

Tan-1 (Fy/Fx)
Y over X

Question 20

Resultant

Answer 20

Square root of Fx + Fy

Question 21

How do you express a physical quantity

Answer 21

Numerical magnitude and a unit

Question 22

What is the precision of an instrument

Answer 22

the smallest non zero reading an instrument can obtain

Question 23

what is the sensitivity of an instrument

Answer 23

ability to detect and respond to the smallest change in the quantity being measured

Question 24

range of an instrument

Answer 24

the difference between the max and min value an instrument can measure

Question 25

random uncertainties occur due to … which causes

Answer 25

the experimenter being unable to repeat his actions precisely which causes a scatter of readings about a mean value

Question 26

systematic uncertainties occur due to

Answer 26

faulty equipment or consistently poor experimental technique

Question 27

rand uncertainties have an equal chance of being

Answer 27

negative or positive that why we use plus or minus

Question 28

Random uncertainties can be reduced by

Answer 28

Taking repeated measurements and finding an average value

Question 29

Systematic uncertainties due to faulty equipment can be reduced and eliminated by

Answer 29

Recalibrating the instruments using standard instruments

Question 30

Systematic uncertainties due poor experimental techniques can be reduced and eliminated by

Answer 30

Better experimental techniques such as eliminating parallax error by taking readings at eye level

Question 31

The absolute values are added when

Answer 31

the quantities are added or subtracted

Question 32

(Uncertainty ques.) When the quantities are multiplied or divided

Answer 32

the fractional uncertainties of the quantities are added

Question 33

Uncertainty ques: when the quantity is raised by a power

Answer 33

the fractional uncertainty is of the quantity is multiplied by
the power.

Question 34

constant errors in one direction are called

Answer 34

systematic errors