Measurments: Chapter # 02
Measurments: Chapter # 02
Measurments: Chapter # 02
MEASURMENTS
Q#1: Choose the correct answer of the statement from the given choices
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
XI.
XII.
XIII.
XIV.
XV.
XVI.
XVII.
XVIII.
XIX.
XX.
XXI.
XXII.
XXIII.
XXIV.
Ans: There are some characteristics of every material object. And we can specify every object according
to the measurement of those characteristics.
Ans: The specific characteristics of every object, which are used to classify or distinct each object from
other objects, are called physical quantities.
Ans: There are two types of physical quantities according to their origin, i.e.
(a)Base Quantities (b) Derived Quantities
Ans: Those Physical Quantities which are specified as basic quantities of any measuring system are called
base physical quantities of that system, e.g. mass, time, length, temperature, intensity of light, etc…
Ans: All those Physical Quantities which are described in terms of Base Physical Quantities in a
measuring system are called derived Physical Quantities, e.g. velocity, acceleration, momentum, force,
volume, etc…
Ans: To measure a physical quantity, we need to compare it with some standard quantity, to see how
many times this quantity is bigger or smaller than the standard quantity. That standard quantity is
known as Unit.
Ans: There are to basic types of units according to their derivation, i.e.
(a)Base Units (b) Derived Units
Ans: The units of Base physical Quantities are called base units. e.g. meter, kilogram, second, candela,
Kelvin, etc…
Ans: The units of derived physical quantities are called derived units.
The units of physical quantities which are derived or () from base units are called derived units, e.g.
meter per second, meter per second per second, meter cube, kilogram meter per second, etc…
Ans: A set of predefined base and derived units is called system of units.
Ans: A system of some kind of standard units, acceptable all over the world, consisting of seven base
units and a number of derived units, is known as international system of units. It abbreviated as S.I.
XII. Write the names and units of base physical quantities of SI?
Ans: one meter is the distance travelled by light in vacuum during a time of 1/299,792,2458 second.
Ans: One second is the duration during which light travels a distance of 299,792,458 meter in vacuum.
OR
One second is the duration in which the cesium-133 atom completes 9,192,631,770 vibrations.
OR
The 1/ 86400 part of a solar day is called the standard one second.
Ans:
XVII. When was the scientists estimated the duration of days of year?
Ans: The scientists measured the time of all the days of year in 1900 A.D.
Ans: The standard measurements of system international are kept at “international bureau of weights
and measures” near Paris.
XIX. Which material is used to manufacture the meter rod, kept at international bureau of weights
and measurements?
Ans: The meter rod, kept at international bureau of weights and measurements, is made of alloy of
platinum and iridium at 0 0C.
Ans: The names of five base physical quantities are as mass, time, length, temperature, intensity of light.
Ans: The names of five derived physical quantities are as velocity, acceleration, momentum, force,
volume.
Ans: The names of five base units are meter, kilogram, second, candela, Kelvin.
Ans: The main advantage of the system international is that its manipulation is quite easy.
Ans: The terms used internationally for the multiples and sub-multiples of various units are called
prefixes.
Ans: The prefixes (multiples and sub-multiples) of different units are obtained simply by multiplying or
dividing with ten or power of ten.
Ans:
Ans: A notation used to express very large or very small values in terms of powers of ten or prefixes is
known as scientific method.
XXIX. What is the internationally accepted method of write any number in scientific notation?
Ans: Internationally accepted method of writing any number in scientific notation is that “there should
be one digit before the decimal point”.
XXX.
XXXI.
XXXII.
XXXIII.
XXXIV.
XXXV.
XXXVI.
XXXVII.
XXXVIII.
XL. b
Long Questions
Q#3: ?
Q#4: ?
Q#5: .
Q#6: ?
Q#7: ?.
Q#8: ?
Q#9: ?