Scientific Study Grade /10 (New Course)

 

      Scientific Study   Grade -10  (New Course)

Scientific Research: " The process by which scientists study various phenomenon using systematic methods of collecting, analyzing, and interpreting data is called scientific Research.
 or 
A systematic and objective efforts to solve a problem or question is called scientific research."

Goals of Scientific Research:
1. Scientific research starts with asking a question.
2. Purpose of research is to get answers of that question.

Characteristics of scientific research:

1.Purposiveness

2.Testibility

3.Emperical Observation (Practical )

4.Replication (Same result, when repeated)

5.Objectivity (No personal feeling)

6.Gernerlization

7.Patience (with pleasure without tention)

8.Expertise

9.Parsimony ( Simplycity in conclusion)

Stages of scientific research:The scientific research includes the following five major steps:
1 Observation
2. Hypothesis
3.Theory
4.Experiments
4.Law
1.OBSERVATION:The process of observing natural phenomenon with the help of five senses and the scientific equipment is called observation.
2. HYPOTHESIS: The explanation of observation and facts is called hypothesis.
3. THEORY: If the hypothesis is accepted it is called theory.
4. EXPERIMENT: Experiments are designed to test the theory. The theory is checked by an experiment.
5. LAW: If predicated results are obtained by experiments, the theory is supposed to be correct and then this theory becomes a law.

Variables: The measurable Elements ,characteristic or properties which can vary and change are direct or indirect related with research and practical works are called variables.  

 Exam score, absenteeism, height, weight, income  water etc.
i .Plant growth is your variable. It can take on different values, like height, weight, or number of leaves.
ii.Fertilizer is another variable, because you can change the amount you give the plants.

Types of variable : The scientific research includes the following
3 types  major variables:
1. Independent Variable:The variable that doesn't depends on other factors during research is called independent variable . •Independent variable influence dependent variable ,because it  is changed/Controlled during study to calculate impact/effect on dependent variable".It is denoted by X
For Example:
i. Hard work leads to success
Hard work =Independent variable
Success =Dependent variable
ii.. Advertisement = Sales
Sales -Dependent Variable
Advertisement=Independent variable
iii. Price = Demand & vice versa

2.Dependent Variable : The variable that  depends on other factors during research is called dependent variable. Dependent variable is influenced by  independent variable.It is denoted by y
For Example:
i. Hard work leads to success
Hard work =Independent variable
Success =Dependent variable
ii.. Advertisement = Sales
Sales- Dependent Variable
Advertisement=Independent variable
iii. Price = Demand & vice versa

3.Controlled variable : A variable is anything that is held constant or limited in a research study is called controlled variable. It is controlled because it could influence the outcomes.
For example :
i..If you are studying the effect of the amount of water on seed germination, control variables might include temperature, light, and type of seed.
ii.In an experiment to observe the growth of a plant, the temperature can be classified as a control variable if it is controlled during an experiment. Other examples of control variables could be the amount of light, duration of the experiment, amount of water, and pot of the plant.

Things to remember related to variable :
1.There should be only one independed variable in an experiment of research work .
2.There should be only one dependent variable in an experiment of research work .
3.The variables except independent variable and dependent variable should be controlled .
4.While presenting the relation between two variable in a graph,dependent variable should be plotted in Y- axis and independent variable is plotted in X- axis .Due to this depnedent variable is called vertical variable and independent variable is called horizontal variable .
5.While expressing the relationship of variable in the formula ,independent variable is written in left side and dependent variable id written on right side of the equation .

Importance of controlling variables : It is important for the researchers to control all the variables except the dependent variables .There are given some importance of controlling variables :
1.It help to establish the causal relationship among the variables of interest
2.It help in avoiding the research bias as slight variations in the research strongly affects the outcomes .

Unit: The known or standard quantity of the same kind with which a physical quantity is

compared  for measuring is called unit .
                                            Or

Word or group of symbols, which represent the quantity uniquely is called unit.

For example: meter(m),kilogram(Kg),second(s) etc.
 

Standard system of unit :There are following 4 types of measurement system of

unit to maintain uniformity in measurement of physical quantity :

1. i)MKS system of unit :The system of unit in which the unit of length is metre

(m),unit of mass is kilogram (Kg) and unit of time is second (S) is MKS system of unit .It

is also called metric system .

ii)CGS system of unit :The system of unit in which the unit of length is centi metre

(cm) ,unit of mass is called gram(gm) and unit of time is called second(s) is called CGS

system .It is also called French system of measurement .

iii)FPS system of unit :The system of unit in which the unit of length is foot (ft) ,unit

of mass is pound (lb) and unit of time is called second(s) is called FPS system of unit .It

is also called British system of measurement .

iv)SI ( systeme  international  de unit or system of international

unit )system of unit: The internationally standardised  unit of measurement

is called SI system of unit .It is established in 1960 A.D. by Geneva Conference

of France .

Advantages of SI system :
i)It help to make the measurement simple and more reliable .
ii)It is help to bring uniformity in measurement and to take the actual measurement .
iii)It is an international system of unit of measurement .
Types of SI unit :The units SI system are divided into two groups:
i.)Fundamental unit :The unit which does not depend upon other unit is called fundamental unit .
Or The unit of fundamental quantities are called fundamental unit. For example: There are seven basic fundamental unit:

S.N.	Fundamental  quantities	Fundamental units(S.I. unit)	symbol
1 2. 3 4 5. 6 7.	Length Mass Time Temperature Electric current Luminous intensity Amount of substance	Meter Kilogram Second Kelvin Ampere Candela mole	M Kg S K A Cd mol

1.)What is the S.I. unit of length ?Why is it called fundamental unit?
Ans. The  S.I. unit of length is meter .
The unit of mass is called fundamental unit because it does not depend on other unit .
2.)Why is the unit of mass is called fundamental unit?
Ans. The unit of mass i.e.kg is called fundamental unit because it does not depend on other unit .
ii)Derived unit : The unit which depend upon the fundamental unit is called derived unit.
Or
The unit of derived quantities  called derived unit .For example:

S.N	Derived quantity	Derived unit(S.I unit)	Fundamental unit involved	Fomula
1. 2. 3. 4. 5.  6.   7. 8. 9.  10.   12.   13.	Area Volume Acceleration Force Density Pressure Work/Energy Moment Power Frequency   Potential difference Electric Resistance	m2 m3 m/s2 Newton(N) Kg/m3  pascal(Pa)or N/m2 Joule(J) N.m Watt or J/S  Hertz(Hz)   Volt(V)   Oham(ῼ)	m.m m.m.m. m.s-2 Kg.m.s-2 Kg.m-3  Kg.m-1s-2   Kg.m2.s-2Kg.m.s-1 Kg.m2s1  1.s-2 or Cycle s-1 Kgm2s-3A-1   Kgm2s-3A-2	A=l×b V=l×b×h a=v-u/t F=m×a D=m/v P=F/A   W=F×d Moment=F×d P=w/t  F=v/λ   P=I/V   R=V/I

1.)What is the S.I. unit of velocity ?Why is it called derived unit ?    
Ans.The s.I. unit of velocity is m/s. The unit of velocity i.e.m/s is derived by combination of fundamental unit i.e. m and s, so it is called derived unit.
2.)What is the S.I.unit of pressure? Why is it called derived unit ?
Ans. The S.I. unit of pressure is Pascal(Pa).
We know that,           P=F/A
Or      P=m x  a/A
 Or P  =Kg.ms^-2/m.m
Or Pressure(  P) =kg.m^-1.s^-2
Therefore ,the unit of pressure i.e. Pa  is called derived unit because it is derived  combination of fundamental unit i.e. Kg .m and s , so it is called derived unit.

Unit analysis of unitwise equation   :The process of checking of  uniformity and validity of formula and equation by analyzing both side of  physical quantity of formula and equation is known as uint analysis of  unitwise equation. for example
i.v = u+at
we know that
or m/s  = m/s+m/s².s
or m/s  =m/s +m/s
or m/s = m/s
ii.s=ut+1/2at² 
we know that 
m =m/s. s+1/2m/s².s²
m =m +1/2 m
m =m
iii.v².  =u².+2as
we know that
or (m/s)².  =(m/s)².+2m/s².m 
or m².s²  =m²s²+2m/s².m 
  m².s² =m².s²

Application of dimensional analysis:
i.It help to checking the dimensional cosistancy of equations.
ii.It help to deducing relation among the physical quantites .

Principle of homogeneity :It states that “If a physical relation is dimentionally correct,then dimensions of each quantity on the left hand side of an equation must be equal to dimensions of each quantity on right hand side.For example :Suppose the three quantites A,B and C ,If C=A+B .According to this principle the dimension of C must be equal to dimension of A and B.

Questions for Practise
A.Multiple Choice Questions
1. Hypothesis is...........
a. tentative assumption                          b. experimental facts
c. discovered facts                                  d. things to be discovered
2.The factor which is changed by the experimenter is.... variable.
a independent                                         b. dependent
c. constant                                               d. extraneous
3.The parameter, often, ignored in the research is... variable.
a. independent                                        b. dependent
c. constant.                                             d. extraneous
4.Which of the following can be reduced further to simplest form?
a. unit of length                                      b. unit of mass
C. unit of time                                        d. unit of acceleration
5. Which of the following unit cannot be expressed in its further simplest form?
a. Kelvin                                                 b. Pascal
C. Cubic meter                                        d. Kilogram per cubic meter
6.Which of the following is not a fundamental unit?
a. Meter                                                 a. Kelvin
c. Mole                                                   d. Radian
7. The unit of luminous intensity is.........
a. Cd                                                       b. cd
C. cD                                                       d. CD
8. The unit of electric current is....
A. ampere                                             b. candela
c. flux                                                    d. watt
9. The standard unit of temperature is....
a. Degree Celsius                                  b. Kelvin
c. Degree Fahrenheit                             d. Degree Kelvin
10. Which of the following relation is true? Provided that, F is force, m is mass, a is acceleration.
a. F= ma                                                b. s = ut + ½ at
c. P=FXA                                              d. A=l³
11. The SI unit of temperature is.....
a) Second                                              b) Kelvin
c) Ampere                                             d) Kilogram
12. Which of the following physical quantity has unit kg/m³?
13. a) Force                                             b) Mass
c) Density                                              d) Acceleration
14. Which of the following is the fundamental unit?
a) Kilogram (kg)                                    b) Newton (N)
c) Pascal (Pa)                                         d) Watt (W)
15. What fundamental units are involved in Joule?
a) kg and m                                           b) kg and s
c) m and s                                              d) kg, m and s
16. Which of the following is a derived unit?
a) Meter (m)                                          b) Second (s)
c) Kilogram (kg)                                   d) Newton (N)
17. Earthquake is measured in........
18. a) Pascal                                            b) Ritcher scale
c) Hertz                                                   d) Kelvin
19. The dimensional formula of power is...
a) [MLT2]                                               b) [ML'T']
c) [ML T³]                                               d) [ML'T]
20. In scientific research, an educated guess about how things work is....
a) Objective                                            b) Hypothesis
c) Result                                                 d) Conclusion
21. A variable that establishes the relation between independent and dependent variable is...
a) dependent variable                             b) independent variable
c) controlled variable                             d) categorical variable
22. The use of a set of units to establish a form of an equation, or more often, to check the answer to a calculation against many simple errors is...
a) dimensional formula                          b) dimensional equation
c) dimensional analysis                         d) principle of homogeneity
23. The number of scientific variables is........
a.2                                                           b.3
c.4                                                          d.10
24.b. Which of the following is not a physical quantity?
a.time                                                     b.love
c.mass                                                   d. length
25.Which of the following is the SI unit of mass?
a.m                                                          b.kg
c.g                                                          d.mg
26. Which of the following is a fundamental unit ?
a. Pa                                                      b. m/s
c. N                                                        d. s
27.Which of the following is a derived unit?
a. S                                                      b. N
c. kg                                                    d. m
28.Which of the following is the SI unit of density?
a. m/s                                                  b. kg/m³
c. g/cm³                                               d. kg m

B. Very short Answer Questions
1. What are variables? Write with examples.
2. Define dependent and independent variables with one example of each.
 3. What is controlled variable? Give one example.
4. What are physical quantities? Give any five examples.
5. Name two types of physical quantities and give two examples of each
6. Define basic or fundamental physical quantities with any three examples
7. Name the seven fundamental physical quantities.
8. Define derived physical quantities with any five examples.
9. What is a unit? Give any three examples.
10. Name two types of units. Also, give any three examples of each.
11. What are fundamental units? Name seven fundamental units of SI
12. What are derived units? Give any five examples.
13. Write down the SI units of the given physical quantities.
a. Mass b. Length c. Length d. Temperature
i. Density e. Pressure f. Volume. g. Force
h.Electric current i.Power
14. Write a short note on "SI system of measurement".
15. What is a scientific research?
16. Name the physical quantities having following units.
a) metre b) gram c) cubic metre
d) kilogram e) litre g) light year
d) second h) Angstrom
17. Name any two physical quantities which have the same dimension.
18. What is measurement?
19. Write the SI units of mass, momentum, pressure and frequency.
20. Mention the fundamental unit of temperature.
21. What is the principle of homogeneity?
22.Define: a) Dimension    b) Dimensional analysis
c) Dimensional formula      d) Dimensional equation
C- Short Questions
.1. Give reason:
a. Scientific variables are very important in scientific learning.
b. Mass and volume are called physical quantities.
c. Length is called a fundamental physical quantity.
d. Pressure is called a derived physical quantity.
e. Kilogram is called a basic or fundamental unit.
f. Pascal is called a derived unit.
g. The unit of temperature is called fundamental unit.
2. Write any two differences between fundamental units and derived units.
3. Differentiate between:
a. Fundamental units and derived units
b. Independent variable and dependent variable
c. Watt and Pascal
d. Control variable and dependent variable
e. Independent variable and control variable
4. Make a list of stages of scientific research.
5.. Derive the dimensional formula of density and acceleration.
3. Why are variables used in scientific investigation?
4. Write importance of measurement in our daily life.
5. Give reason.
a) The unit of force is called a derived unit. Why?
b) The unit of speed is called a derived unit. Why
6. The Weights and Metre scales in the market are checked by Department Standard Weights and Measurements in Nepal in every two years. Why?
7. What are the different steps involved in a scientific study? Show in a flowchart.
8.Write any two importance of controlling the variables in research.
9.Analyze the relation, v²=u²+2as, using unit analysis.
D- Long Answer Questions.
1. Find out the fundamental units involved in the given derived units.
a. Newton                                            b. Pascal
C. watt                                                 d. joule
e. cubic metre
2. Find out the fundamental units involved in the units of
. a. Velocity                  b. Acceleration                   c. power
d. work                              e. pressure                         g. volume
h. Force                            i. Density                             j. square metre.
3. List the fundamental units included in pascal (Pa) and watt (W).
4. Analyze the given equations and check their homogeneity and validity.
a. v=u+at b. s ut + 1/2 at?
c. v²=u²+2as
5. Resolve following derived units into fundamental units.
a) Watt                                       b) Metre/second
c) Newton meter                         d) Newton
e) Cubic metre                            f) Pascal
g) Joule                                         h) Hertz
6. Describe different stages of scientific research.
 4. What are the variables used in scientific research? Discuss in brief.
5.Do you agree with the statement "Independent variable is the cause variable and the dependent variable is the effect variable"? Put your views forward.