Page 1
Physical Quantities
• The quantities that can be measured
are called physical quantities. For
measuring the physical quantities, we
require magnitude and a fixed unit. For
example, If the distance from London to
Reading is 275 km, so the magnitude is
275 and its unit is km here.
• The specific physical quantities that
cannot be expressed in any other
quantity are called fundamental
physical quantities. Some fundamental
physical quantities are mass, length,
time and temperature.
Page 2
Physical Quantities
• The quantities that can be measured
are called physical quantities. For
measuring the physical quantities, we
require magnitude and a fixed unit. For
example, If the distance from London to
Reading is 275 km, so the magnitude is
275 and its unit is km here.
• The specific physical quantities that
cannot be expressed in any other
quantity are called fundamental
physical quantities. Some fundamental
physical quantities are mass, length,
time and temperature.
Traditional Units
of Measurement
In ancient times, people use their hands, arms and feet to
measure the quantities. These methods still use in the present
time. The units that we measure through these methods are
yards, cubit and handspan.
Units Description
Yard The distance between the endpoint of an outstretched arm to the
tip of the nose.
Cubit The distance between the elbow to the tip of the middle finger.
Foot Measurement of the quantity by a barefoot of an adult person.
Handspan The measurement of a quantity by the tip of the thumb to the tip
of the little finger when the palm is outstretched.
Page 3
Physical Quantities
• The quantities that can be measured
are called physical quantities. For
measuring the physical quantities, we
require magnitude and a fixed unit. For
example, If the distance from London to
Reading is 275 km, so the magnitude is
275 and its unit is km here.
• The specific physical quantities that
cannot be expressed in any other
quantity are called fundamental
physical quantities. Some fundamental
physical quantities are mass, length,
time and temperature.
Traditional Units
of Measurement
In ancient times, people use their hands, arms and feet to
measure the quantities. These methods still use in the present
time. The units that we measure through these methods are
yards, cubit and handspan.
Units Description
Yard The distance between the endpoint of an outstretched arm to the
tip of the nose.
Cubit The distance between the elbow to the tip of the middle finger.
Foot Measurement of the quantity by a barefoot of an adult person.
Handspan The measurement of a quantity by the tip of the thumb to the tip
of the little finger when the palm is outstretched.
Standard Units of Measurement
Quantities SI units Symbol
Length metre m
Mass kilogram kg
Time second s
The standard units of measurement
introduced to measure accurate quantity of
any object.
In 1960, the General Council of Weights and
Measures organized where all the scientists
gathered to decide the uniform system of
units acceptable all over the world.
Page 4
Physical Quantities
• The quantities that can be measured
are called physical quantities. For
measuring the physical quantities, we
require magnitude and a fixed unit. For
example, If the distance from London to
Reading is 275 km, so the magnitude is
275 and its unit is km here.
• The specific physical quantities that
cannot be expressed in any other
quantity are called fundamental
physical quantities. Some fundamental
physical quantities are mass, length,
time and temperature.
Traditional Units
of Measurement
In ancient times, people use their hands, arms and feet to
measure the quantities. These methods still use in the present
time. The units that we measure through these methods are
yards, cubit and handspan.
Units Description
Yard The distance between the endpoint of an outstretched arm to the
tip of the nose.
Cubit The distance between the elbow to the tip of the middle finger.
Foot Measurement of the quantity by a barefoot of an adult person.
Handspan The measurement of a quantity by the tip of the thumb to the tip
of the little finger when the palm is outstretched.
Standard Units of Measurement
Quantities SI units Symbol
Length metre m
Mass kilogram kg
Time second s
The standard units of measurement
introduced to measure accurate quantity of
any object.
In 1960, the General Council of Weights and
Measures organized where all the scientists
gathered to decide the uniform system of
units acceptable all over the world.
Other SI systems
• The measurement of smaller quantities is
called submultiples of units. They represent
with the factor of 1/10, 1/100 and 1/1000, etc.
• The measurement of larger quantities is called
multiples of units. They represent with the
factor 10, 100 and 1000, etc.
• Both multiples and submultiples have prefixes
and symbol.
Prefixes Symbol Submultiples/Multiples
deci d Submultiple: 1/10
centi c Submultiple: 1/100
milli m Submultiple: 1/1000
Kilo k Multiple: 1000
Hecto h Multiple: 100
Mega M Multiple: 10000
Terms Description
CGS Centimetre for length, Gram for mass and Second for time
MKS Metre for length, Kilogram for mass and Second for time
FPS Foot for length, Pound for mass and Second for time
Page 5
Physical Quantities
• The quantities that can be measured
are called physical quantities. For
measuring the physical quantities, we
require magnitude and a fixed unit. For
example, If the distance from London to
Reading is 275 km, so the magnitude is
275 and its unit is km here.
• The specific physical quantities that
cannot be expressed in any other
quantity are called fundamental
physical quantities. Some fundamental
physical quantities are mass, length,
time and temperature.
Traditional Units
of Measurement
In ancient times, people use their hands, arms and feet to
measure the quantities. These methods still use in the present
time. The units that we measure through these methods are
yards, cubit and handspan.
Units Description
Yard The distance between the endpoint of an outstretched arm to the
tip of the nose.
Cubit The distance between the elbow to the tip of the middle finger.
Foot Measurement of the quantity by a barefoot of an adult person.
Handspan The measurement of a quantity by the tip of the thumb to the tip
of the little finger when the palm is outstretched.
Standard Units of Measurement
Quantities SI units Symbol
Length metre m
Mass kilogram kg
Time second s
The standard units of measurement
introduced to measure accurate quantity of
any object.
In 1960, the General Council of Weights and
Measures organized where all the scientists
gathered to decide the uniform system of
units acceptable all over the world.
Other SI systems
• The measurement of smaller quantities is
called submultiples of units. They represent
with the factor of 1/10, 1/100 and 1/1000, etc.
• The measurement of larger quantities is called
multiples of units. They represent with the
factor 10, 100 and 1000, etc.
• Both multiples and submultiples have prefixes
and symbol.
Prefixes Symbol Submultiples/Multiples
deci d Submultiple: 1/10
centi c Submultiple: 1/100
milli m Submultiple: 1/1000
Kilo k Multiple: 1000
Hecto h Multiple: 100
Mega M Multiple: 10000
Terms Description
CGS Centimetre for length, Gram for mass and Second for time
MKS Metre for length, Kilogram for mass and Second for time
FPS Foot for length, Pound for mass and Second for time
Measuring Length
The measurement of length concerns the length, width, thickness, height and distance
of any object.
There are several instruments used to measure the length. For example, a ruler, metre
rod and a measuring tape, etc.
• A ruler has units of centimeter and millimeter.
It is used to measure smaller quantities
• A meter rod is used by tailors to measure the
length of the cloth. The unit of meter rod is
fixed to one meter.
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