C8 1.Measurement
1. Define physical quantity with
examples.Ans: The quantity which can be measured directly or indirectly is called physical quantity.
For example: Length, Mass, Time, Luminous Intensity, etc.
2. Write the types of physical quantities.
Ans: There are two types of physical quantities.They are:
-Fundamental physical quantity
-Derived physical quantity
3. Define area and volume.
-Fundamental physical quantity
-Derived physical quantity
3. Define area and volume.
Ans: The surface covered by an object is called area.
The space occupied by an object is called volume.
4. What do you mean by fundamental physical quantity and derived physical quantity? Give examples of each.
The space occupied by an object is called volume.
4. What do you mean by fundamental physical quantity and derived physical quantity? Give examples of each.
Ans: Those physical quantities which do not depend upon other physical quantities and exist independently are called fundamental physical quantities.For example : length, time, temperature, Mass, etc.
Those physical quantities which are to be expressed in terms of other fundamental quantities or exists by combination of fundamental quantities are called derived physical quantities. For example: area, velocity, volume, density, acceleration, etc.
5. Define measurement and unit.
Those physical quantities which are to be expressed in terms of other fundamental quantities or exists by combination of fundamental quantities are called derived physical quantities. For example: area, velocity, volume, density, acceleration, etc.
5. Define measurement and unit.
Ans. The process of comparing a physical quantity with known standard quantity of the same kind is called measurement.
Unit is a fixed definite quantity which is used as standard of reference to measure the quantity of same kind.
6. What do you mean by SI unit?
Unit is a fixed definite quantity which is used as standard of reference to measure the quantity of same kind.
6. What do you mean by SI unit?
Ans: The extended form of MKS system which is derived in order to maintain uniformity in the measurement of fundamental quantities is SI unit. It consists of seven fundamental units. They are Kilogram (kg), meter(m), second(s), candela (cd), ampere(a), mole(mol), Kelvin(K).
7. What is the importance of measurement?
7. What is the importance of measurement?
Ans: The importance of measurement are as follows:
-It helps in buying and selling of goods.
-It is important in performing scientific experiments to establish truth about the physical phenomenon.
-It is used to obtain accurate results about physical quantities.
-It helps in performing experiments for making our daily food easier.
8. Define fundamental and derived quantities with two examples of each.
-It helps in buying and selling of goods.
-It is important in performing scientific experiments to establish truth about the physical phenomenon.
-It is used to obtain accurate results about physical quantities.
-It helps in performing experiments for making our daily food easier.
8. Define fundamental and derived quantities with two examples of each.
Ans: Those units which are used to measure the fundamental physical quantities and which do not depend on other units are called fundamental units. For example: Meter, second, kilogram,etc.
Those units which are used to measure the derived physical quantities and which depends on other units are called derived units. For example:Area,Volume, Power,etc.
9. What is the standard unit used to measure the mass?
Those units which are used to measure the derived physical quantities and which depends on other units are called derived units. For example:Area,Volume, Power,etc.
9. What is the standard unit used to measure the mass?
Ans:The standard unit used to measure the mass is kilogram(kg).
10. The unit of the area is derived unit. Why?
10. The unit of the area is derived unit. Why?
Ans: The unit of area is derived unit because the unit of area can be expressed by multiplying two fundamental units of length i.e, meter. Hence, unit of area is a derived unit.
11. What is the SI unit of current?
11. What is the SI unit of current?
Ans: The SI unit of current is Ampere(A).
12. Define: a. length, b. Mass c. Time
a. Length: Length is defined as the the distance between two points.
b. Mass:Mass is defined as the quantity of matter contained in the body.
c. Time: Time is the duration between two events.
a. Length: Length is defined as the the distance between two points.
b. Mass:Mass is defined as the quantity of matter contained in the body.
c. Time: Time is the duration between two events.
13. Write some formula used to
calculate the area of a regular object?
Ans: Some formula used to calculate the are of regular objects are:
A= l×b, A = 1/2 b×h, A= l2 etc.
14. Name the fundamental units involved in the unit of force.
A= l×b, A = 1/2 b×h, A= l2 etc.
14. Name the fundamental units involved in the unit of force.
Ans: the fundamental units involved in the unit of force are: Kg, m and s.
15. Distinguish between fundamental and derived unit.
15. Distinguish between fundamental and derived unit.
Ans: The differences between fundamental and derived units are:
16. Distinguish between mass and
weight.
Ans: The differences between mass and weight are:
Fundamental units
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Derived units
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1. The units of fundamental quantities are called fundamental units
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1. The units of derived quantities are called derived units.
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2. These units are independent of each other.
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2. These units are obtained one or more fundamental units i.e these
depend upon each other.
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3. Examples: second, kilogram, Kelvin, mole etc.
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3. Examples: Joule, watt, Newton etc.
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Ans: The differences between mass and weight are:
S.no
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Mass
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Weight
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1
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It is the quantity of matter contained in a body.
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It is the amount of force of gravity acted on a body.
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2
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Mass of an object does not vary from place to place
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Weight of an object varies from place to place.
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3
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Mass is scalar quantity
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Wight is the vector quantity.
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4
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Mass is measured by beam balance.
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It is measured by spring balance.
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5
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There is no place or condition under which mass of an object be zero.
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Weight of an object will be zero, at the centere of the earth or at the place where R = 0.
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6
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The SI unit of mass is kilogram(Kg).
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The SI unit of weight is Newton(N).
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Ans: The differences between density and relative density are:
Density
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Relative density
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1. It is the mass per unit volume.
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1. It is the ratio of density of a substance to the density of water at 4°C.
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2. It can be expressed as: $D=\frac{m}{v}$
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2. It can be expressed as: $R.D=\frac{\text{Density of substance}}{\text{density of water at 4}{}^\circ \text{C}}$
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3. Its SI unit is kg/ m3.
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3. It has no unit.
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18. Define: a. 1 Kg b. 1 m c. 1 s
Ans:
a. One kg: One standard kilogram is the mass of Platinum Iridium cylinder of length equal to height at the international bureau of weights and measures in France. This cylinder is about 4 cm height with a diameter of 4 cm.
b. One meter: One standard metre is the distance between two fine gold lines on Platinum-Iridium rod at 0°C, which is kept at international bureau of weight and measure in France.
c. One second: One standard second is the time taken by 9192631770 vibrations of the radiation emitted by Cesium - 133 atom.
Ans:
a. One kg: One standard kilogram is the mass of Platinum Iridium cylinder of length equal to height at the international bureau of weights and measures in France. This cylinder is about 4 cm height with a diameter of 4 cm.
b. One meter: One standard metre is the distance between two fine gold lines on Platinum-Iridium rod at 0°C, which is kept at international bureau of weight and measure in France.
c. One second: One standard second is the time taken by 9192631770 vibrations of the radiation emitted by Cesium - 133 atom.
19. What is SI system? Write the differences between SI system and CGS system.
Ans: Scientists all over the world realized the necessity of common system of units for the sake of uniformity and convenience. So, in 1960 AD, the eleventh general conference of scientists held on France recommended a common system of units. It is an extended form of metric system ie. MKS which is called SI system.
CGS system is the French system of measurement. In this system, the unit of length is centimetre(cm), mass is gram(gm) and time is second (s).
20. What is mass? Write its SI unit.
Ans: It is the quantity of matter contained in a body. It is a scalar constant quantity ie. it does not vary from place to place. It is measured by beam balance. There is no place or condition under which mass of an object be zero. Its SI unit is kilogram (kg).
21. What do you mean by physical quantity?
21. What do you mean by physical quantity?
Ans: The quantity that can be measured directly or indirectly is called physical quantity. Examples: area, density, volume, pressure etc.
22. What is density? Define relative density.
22. What is density? Define relative density.
Ans:
Density:
Density is defined as the mass per unit volume. Its is scalar quantity. Its SI unit is kg / m3. Mathematically,
Density $D=\frac{M}{V}$
Relative density:
Relative density is defined as the ratio of density of a substance to the density of water at 4°C.
Mathematically,
Relative density \[\text{R}\text{.D}=\frac{\text{Density of substance}}{\text{Density of water at 4 }\!\!{}^\circ\!\!\text{ C}}\]
Relative density has no unit because it the ratio between two densities.
Meaning of Relative Density:
Density:
Density is defined as the mass per unit volume. Its is scalar quantity. Its SI unit is kg / m3. Mathematically,
Density $D=\frac{M}{V}$
Relative density:
Relative density is defined as the ratio of density of a substance to the density of water at 4°C.
Mathematically,
Relative density \[\text{R}\text{.D}=\frac{\text{Density of substance}}{\text{Density of water at 4 }\!\!{}^\circ\!\!\text{ C}}\]
Relative density has no unit because it the ratio between two densities.
Meaning of Relative Density:
- If a substance has relative density less then 1, it will float in the liquid taken.
- If a substance has relative density equal to 1, it will float with completely immersed in the liquid.
- If a substance has relative density greater then 1, it will sink in the liquid.
Ans:
a. FPS system: It is the British system of unit. In this system, the unit of length, mass and time are foot (ft), pound (lb) and second (s) respectively.
a. FPS system: It is the British system of unit. In this system, the unit of length, mass and time are foot (ft), pound (lb) and second (s) respectively.
b. MKS system: In this system the units of the length, mass and time are meter (m), kilogram (kg) and second (s) respectively. In our country Nepal, M.K.S system is used as the standard for measuring physical quantities.
c. SI system: Scientists all over the world realized the necessity of common system of units for the sake of uniformity and convenience. So, in 1960 AD, the eleventh general conference of scientists held on France recommended a common system of units. It is an extended form of metric system (MKS). This conference defined various quantities and ready to provide sample of defined quantities to every-nation. Thus, it provides the uniformity on measurement.
d. CGS system: It is the French system of unit. In this system, the unit of length is centimetre (cm) that of mass is gram (gm) and time is second (s).
24. Define a light year. What quantity does it measure?
24. Define a light year. What quantity does it measure?
Ans: Light year is the distance traveled by light in one year. It is used to measure the large distances such as distance between two planets, tow stars etc. One light year equal to 9.46×10^15 meter.
25. Name the instruments that are used for the measurement of volume of liquid.
25. Name the instruments that are used for the measurement of volume of liquid.
Ans:The instruments that are used to measure the volume of liquid are measuring cylinder, burette, pipette, volumetric flask etc.
26. How is the volume of an irregular body determined?
26. How is the volume of an irregular body determined?
Ans:The volume of an irregular body is determined by immersing the irregular object into a measuring cylinder by water displacement method.
27. Give the derived units of: a. Pressure b. Force c. power
Ans: The derived units of:
a. Pressure: $\frac{Kg}{m{{s}^{2}}}$
b. Force: $\frac{Kgm}{{{s}^{2}}}$
c. Power: $\frac{Kg{{m}^{2}}}{{{s}^{2}}}$
27. Give the derived units of: a. Pressure b. Force c. power
Ans: The derived units of:
a. Pressure: $\frac{Kg}{m{{s}^{2}}}$
b. Force: $\frac{Kgm}{{{s}^{2}}}$
c. Power: $\frac{Kg{{m}^{2}}}{{{s}^{2}}}$
28. Define SI units. What are the
other basic units involved in it?
Ans:Scientists all over the world realized the necessity of common system of units for the sake of uniformity and convenience. So, in 1960 AD, the eleventh general conference of scientists held on France recommended a common system of units. It is an extended form of metric system (MKS).
The other basic units involved in it are: Amount of substance (mol), Electric current (A), Luminous intensity (cd), and Temperature (K).
Ans:Scientists all over the world realized the necessity of common system of units for the sake of uniformity and convenience. So, in 1960 AD, the eleventh general conference of scientists held on France recommended a common system of units. It is an extended form of metric system (MKS).
The other basic units involved in it are: Amount of substance (mol), Electric current (A), Luminous intensity (cd), and Temperature (K).
Q1 Aayusha katwal : Physical quantity is quantity which can be measured directly or indirectly. For example:density, area,volume, time etc.
ReplyDeleteQ2 Aayusha katwal : The types of physical quantity are :
ReplyDelete1) Fundamental physical quantity
2) Derived physical quantity
Q3 Aayusha katwal: The surface covered by an object is called area.
ReplyDeleteThe space occupied by an object is called volume.
Q4 Aayusha katwal : Those physical quantities which do not depend upon other fundamental quantities are called fundamental physical quantity.For example : length,time,temperature,etc.
ReplyDeleteThose physical quantities which are to be expressed in terms of other fundamental quantities are called derived physical quantities. For example: area , velocity,volume,density etc.
Q5 Aayusha katwal: The process of comparing a physical quantity with known standard quantity of the same kind is called measurement.
ReplyDeleteUnit is a fixed definite quantity which is used as standard of reference to measure the quantity of same kind.
Q1 Sandhya Khatiwada:The quantity which can be measured directly is called physical quantity.
ReplyDeleteFor example: Length,Mass, Time,Luminous Intensity,etc.
Q1 Sandhya Khatiwada:The quantity which can be measured directly or indirectly is called physical quantity.
ReplyDeleteFor example: Length,Mass, Time,Luminous Intensity,etc.
Q2 Sandhya Khatiwada:There are two types of physical quantities.They are:
ReplyDelete-Fundamental physical quantity
-Derived physical quantity
Q3 Sandhya Khatiwada:
ReplyDeleteThe surface covered by an object is called area.
The space occupied by an object is called volume.
Q4 Sandhya khatiwada:
ReplyDelete-Those physical quantities which do not depend upon other fundamental quantities are called fundamental physical quantities.For example : length,time,temperature,Mass,etc.
-Those physical quantities which are to be expressed in terms of other fundamental quantities are called derived physical quantities. For example: area,velocity,volume,density,acceleration, etc.
Q5 Sandhya khatiwada:
ReplyDelete-The process of comparing a physical quantity with known standard quantity of the same kind is called measurement.
Unit is a fixed definite quantity which is used as standard of reference to measure the quantity of same kind.
Q6 Sandhya khatiwada:
ReplyDelete-SI Unit:The extended form of MKS system which is derived in order to maintain uniformity in the measurement of fundamental quantities is SI unit.
Q7 Sandhya khatiwada:The importance of measurement are as follows:
ReplyDelete-It helps in buying and selling of goods.
-It is important in performing scientific experiments to establish truth about the physical phenomenon.
-It is used to obtain accurate results about physical quantities.
-It helps in performing experiments for making our daily food easier.
Q8 Sandhya khatiwada:
ReplyDeleteFundamental units: Those units which are used to measure the fundamental physical quantities and which do not depend on other units are called fundamental units. For example:Meter, second, kilogram,etc.
Derived units: Those units which are used to measure the derived physical quantities and which depends on other units are called derived units. For example:Area,Volume,Power,et
Q9 Sandhya khatiwada:
ReplyDeleteThe standard unit used to measure the mass is kilogram(kg).
Q10 Sandhya khatiwada:
ReplyDeleteThe unit of area is derived unit because the unit of area can be expressed by two fundamental units of length i.e, meter.
Hence, unit of area is a derived unit.
Q11 Sandhya khatiwada:
ReplyDeleteThe SI unit of current is Ampere(A).
Q12 Sandhya khatiwada:
ReplyDelete-Length:
Length is the distance between two points.
-Mass:
Mass is the unit of matter contained in the body.
-Time:
Time is the duration between two events.
1 Gaurav Neupane: The quantity which can be measured is called physical quantity. for example: length,volume,area,etc
ReplyDelete2 Gaurav Neupane: There are 2 types of physical quantity.they are:
ReplyDelete1.Fundamental Physical quantity
2. Derieved physical quantity
4. Gaurav Neupane: Those quantity which don't depend upon other physical quantity are called fundamental physical quantity.
ReplyDeleteThose quantity which depend upon other physical quantity are called derived physical quantity. example of fundame tal quantity: meter kilogram etc.
example fo derived quantity:area volume power etc.
3. Gaurav Neupane:The surface covered by an object is called area. The space occupied by an object is called mass.
ReplyDelete5. Gaurav Neupane: The comparison of unknown quantity to known standard physical quantityiscalled measurement.
ReplyDeleteUnit is a fixed definite quantity which is used as standard reference of to measure the quantity of same kind.
Qno.1 [Minu Tamang]:Physical quantity is quantity which we can be directly measured or in directly.Example:area,volume,time,etc.
ReplyDeleteQno.2[Minu Tamang]:The types of physical quantities are: 1:Fundamental physical quantities 2:Derived physical quantities
ReplyDeleteQno.3[Minu Tamang]:Area:The surface cover by an object is called area. Volume:The space occupied by an object is called volume.
ReplyDeleteQno.4[Minu Tamang]:Those physical quantities which do not depend on other fundamental quantities are called fundamental physical quantities.Example:length,time.etc.
ReplyDeleteThose physical quantities which are to be expressed in terms of other fundamental quantities are called derived physical quantities.Examaple:area,volume,etc.
Qno.5[Minu Tamang]:The process of comparing a physical quantity with known standered quantity of the same kind is called measurement.
ReplyDeleteUnit is a fixed definite quantity witch is used as standered reference of to measure the quantity of same kind.
correct
Delete01 Sushmita:Physical quantity is the quantity which can be measured directly or indirectly.
ReplyDeleteFor e.g:area,mass,length etc.
02 Sushmita Ghimire:There are two types of physical quantity.They are:
ReplyDelete1:Fundamental quantity
2:Derived quantity
03 Sushmita Ghimire:The surface covered by an object is called area.
ReplyDeleteThe space occupied by an object is called volume.
04 Sushmita Ghimire:Those physical quantity which don't depend upon other quantities are called fundamental physical quantity.
ReplyDeleteFor e.g:Length,Mass,Temperature etc.
Those physical quantities which are to be expressed in terms of other fundamental quantities are called derived physical quantity.
For e.g:Velocity,Area,Volume etc.
05 Sushmita Ghimire:The process of comparing a physical quantity with known standard quantity is called measurement.
ReplyDeleteUnit is a fixed definte quantity which is used as standard of reference to measure the quantity of same kind.
Q1=Physical quantity is quantity which can be measured directly or indirectly. For example:density, area,volume, time etc.
ReplyDeleteQ2=
ReplyDeleteQ2=The types of physical quantity are :
ReplyDelete1) Fundamental physical quantity
2) Derived physical quantity
Q3=The surface covered by an object is called area.
ReplyDeleteThe space occupied by an object is called volume.
Q4=Those physical quantity which don't depend upon other quantities are called fundamental physical quantity.
ReplyDeleteFor e.g:Length,Mass,Temperature etc.
Those physical quantities which are to be expressed in terms of other fundamental quantities are called derived physical quantity.
For e.g:Velocity,Area,Volume etc.
correct
DeleteQ5=The process of comparing a physical quantity with known standard quantity of the same kind is called measurement.
ReplyDeleteUnit is a fixed definite quantity which is used as standard of reference to measure the quantity of same kind.
01=The quantity which can be measured directly indirectly is called physical quantity
ReplyDeleteFor example:Density,area,volume,etc.
02 Sujan Budhathoki: The types of physical quatities are
ReplyDelete1.Fundamental physical quantity
2.Derived physical quantity
03 Sujan Budhathoki:The surface covered by an object is called area.
ReplyDeleteThe space occupied by an object is called volume.
04 Sujan Budhathoki:Those physical quantities which do no depend upon other quantities are called fundamental quantities
ReplyDeleteFor example:Length,Mass,Temperature,etc.
Those physical quantities which are to be expressed in terms of other fundamental quantities are called derived physical quantity
For example:Velocity,Area,Volume,etc.
correct
ReplyDelete6.Gaurav Neupane The extended form of MKS system which is derived in order to maintain uniformity in the measurement of fundamental quantities is SI unit.
ReplyDelete7. Gaurav Neupane The importance of measurement are÷
ReplyDelete1.-It is important in performing scientific experiments
2. It is important while buying,sellingand exchanging goods
3. measurement of time is important while working.
4. It is important while cooking food
8. Gaurav Neupane:The fundamental are those which are used to measure the fundamental physical quantity and which donot depend on other quantites
ReplyDeletefor example. metere,second,kilogram
Those units which are used to .easure the derieved physical quantity and donot depend upon others is called derieved quantity
for example. area,volume,power
10. Gaurav Neupane:The unit of area is derieved unit because the unit of area can be expressed by multiplying two fundamental units of length i.e,meter
ReplyDeleteSo,unit of area is derived unit
11. Gaurav Neupane: The SI unit of current is emperor(e)
ReplyDelete12. Gaurav Neupane: Length is defined as the distance between two points
ReplyDeleteb. mass is the quantity of matter contained in a body
c. Time is a duration between two events
Q no.6[Minu Tamang]The extend formof MKS system which is derived in order to maintain uniformity in the measurement of fundamental quantities is SI unit.It consists of seven fundamental units.They are kilogram[kg],meter[m],second[s],candela[cd],ampere[a],mole[mol],kelvin[k].
ReplyDeleteQ no.7[Minu Tamang]The importance of measurement are as follows: 1.It helps in buying and selling goods. 2.It is important in performing scientific experiments to establish truth about the physical phenomenon. 3.Iit is used to obtain accurate results about physical quantities. 4.It helps in performing experiments for making our daily food easier.
ReplyDeleteQno.8[Minu Tamang]Those unit which are used to measure the fundamental physical quantities nad which do not depend on other unit are called fundamental units.For eg;Meter,second,kilogram,etc.
ReplyDeleteQno.9[Minu Tamang]The standered unit used to measure the mass is kilogram[kg]
ReplyDeleteQno.10[Minu Tamang]The unit of area is derived unit because the unit of area can be expressed by multiplying two fundamental units of length i.e,Meter.Hence,unit of area is a derived unit.
ReplyDeleteQno.11[Minu Tamang]The SI unit of current is Ampere[A].
ReplyDeleteQno.12[Minu Tamang] Length:Length is defined as the distance between two options. Mass:Mass is defined as the quantity of matter contained in a body. Time:Time is the duration between two events.
ReplyDeleteSafal kc :
ReplyDeleteMeasurement is the process of comparing a unknown physical quantity with a known standard quantity
The SI unit of current is Kelvin (k )
The importance of measurement are;
It helps in buying and selling goods
It is important in performing scientific experiment for establishing truth about the physical pheno Menon
It helps to obtain accurate results about physical quantity
Those quantities which do not depend upon other quantities are called fundamental quantity
Those quantities which are to be expressed in the terms of other fundamental quantity are called derived quantity
Mass is the matter contained in a body.its si unit is kilogram kg
Those quantities which can be measured directly or indirectly are called physical quantity
Density is defined as the mass per unit volume
Relative density is defined as the ratio between the density of a body to the density of water at 4 °c
The types of physical quantity are
Fundamental quantity and derived physical quantity
Area is the surface covered by a body
The space occupied by a body is called volume
Unit is a fix definite quantity which is used as standard of reference to measure the quantity of same kind
The extended form of mks system which is derived in order to maintain uniformity in the measurement of fundamental quantities is called SI unit.
The unit of area is derived because the unit of area can be expressed by multiplying two fundamental units
Length is defined as the distance between two points
Mass is defined as the matter contained in a body
Time is the duration between two events
Some formulas used to measure area of a regular object are
A=l*b
A=1/2 b*h
A= l2
Fundamental units involved in the unit of force are kg , m ,s
Define 1kg ..one standard kilogram is the mass of platinum iridium cylinder of length equal to height of the international bureau of the weight and measures in France ..the cylinder is about 4cm height and diameter At 4cm
One meter : one standard metre is the distance between two fine gold lines on platinum iridium rod at 0°c which is kept in international bureau of weight and measure in France
One standard second is the time taken by 9192631770 vibration of the radiation emmited by cesium 133 atom
Light year is the distance travelled by light in one year .. it is used to measure the large distances such as distance between two planets or distance between two stars etc one light year equals to 9.45*10^15 metre
The instruments that are used to measure a volume of a liquid are :
Measuring cylinder
Burette
Pipette
Volumetric flask
The volume of an irregular body is determined by immersing the irregular object into a measuring cylinder by water displacement method ..
Pressure = kg/Ms ^2
Force = kgm / s ^2
Power = kgm^2/ s^2
Scientist all over the world realised the neccesity of common units for the sake of uniformity and convinence so I. 1960 . The eleventh general conference of scientist held in France recommended
A common system of units . It is an extended form of metric system i.e MKS system of measurement is called SI