Measurement
Fundamental unit:
Those units which are independent to other unit are called fundamental unit. Eg: meter, centimeter,kg, gram,second
Derived Unit:
Those units which are derived from fundamental units are called derived unit. Eg: Area, Volume, Force, Density, velocity, etc
1) What is mass? Write any two differences between fundamental unit and derived unit.
Ans: Mass is defined as the total amount of matter contain in a body. It’s SI unit is ‘kg’.
2) Define physical quantity.
Ans: The measureable quantity is called physical quantity. Length, Mass, Time, Density, etc.
3) What is mass? Write any two differences between fundamental unit and
derived unit.
Ans: Mass is defined as the total amount of
matter contain in a body. It’s SI unit is ‘kg’.
|
S.No |
Fundamental Unit |
Derived Unit |
|
1 |
They are independent to other. |
They are dependent with other. |
|
2 |
Eg, meter, kilogram, second |
Eg, m3, N, N/m3 |
4) What is weight?
Ans: The pulling force exerted by earth on an object is called weight. Its SI unit is Newton.
5) What is SI system?
Ans: The improved and extended version of MKS system is called SI system.
6) What is time?
Ans: The duration between any two event is called time.
7) What is MKS system?
Ans: The system in which length is measured in meter, mass in kilogram and time in second is called MKS system.
8) What is CGS system?
Ans: The system in which length is measured in centimeter, mass in gram and time in second is called CGS system.
9) Describe the importance of measurement in our daily life.
Ans: We use measurement system in our daily activities. We need measurement while selling or buying goods, playing, and drawing. We also get accurate physical quantities with the help of measurement.
10) Deifne solar day.
Ans: A solar day is defined as the time interval between the consecutive passages of the sun through the zenith.
11) Write the fundamental units involved in Newton. How is the volume of irregular solid object measured? Write.
Ans: The fundamental units involved in Newton are kg.m/s2.
The volume of an irregular object is measured with the help of measuring cylinder by water displacement method.
12) What is measurement?
Ans: The process of comparison of unknown quantity with known fixed standard quantity is called measurement.
13) What is regular object?
Ans: The object which have fixed length, breadth, height or a definite geometrical shape is called regular object.
14) How is the area of an irregular object determined?
Ans: The area of an irregular object is determined by using a graph paper.
15) Why the unit of density called derived unit?
Ans: The unit of density is called derived unit because it's SI unit is kg/m3 which is formed by the combination of fundamental units ‘kg’ and ‘m’.
16) Why is the unit of mass called fundamental unit?
Ans: The unit of mass is called fundamental unit because its SI unit (kg) is independent with other units.
17) Weight of an object varies from place to place on the earth, why?
Ans: Earth is not a perfect sphere. This causes the variation in the value of acceleration due to gravity at different places. Due to this, weight of an object varies from place to place on the earth.
18) What is volume? Write its SI and CGS unit.
Ans: The space occupied by a body is called its volume. Its SI unit is m3 and CGS unit is cm3.