Unit 1                         Scientific Learning

Multiple choice questions
A. Choose the correct alternatives of the following questions. Correct answer is

underlined below.

1. The variable whose value can be determined by the user is called ………..…….. variable.
a. dependent          b. independent        c. controlled         d. constant

2. The Brave all that can be controlled while doing the experiment is called …………… variable.
a. independent       b. control                  c. dependent       d. control and dependent

3. How many types of variable are there?
a. one                       b. four                        c. two                   d. three

4. The variable whose value depends on other variables and the users cannot

determine its value directly is called …………….. variable.
a. dependent          b. controlled             c. independent  d. constant

5. In a research question, ‘effect of physical exercise in the Heartbeat’, which of

the following is the independent variable.(A) or
a. type of physical exercise                   b. duration of physical exercise in minute
   c. number of Heartbeat per minute    d.  both b and c

6. In a research question, ‘what is the effect of heart on the solubility of sugar? ‘ identify the independent and dependent variables.
a. temperature of water (°C)
b. amount of sugar that can dissolve completely in the water(in gram)
c. amount of water
d. temperature of sugar

a. (i) and (ii)         b. (i) and (iii)        c. (ii) and (i)          d. (iii) and (iv)

7. The unit of length is called of fundamental unit ,because
a. it depends on other units of measurement.
b. it does not depend on other units of measurement.
c. it is easy to measure.
d. it depends only on to units of measurement.

8. Identify the fundamental units involve in the unit Newton (N).
a. kg, m and s             b. kg, m and cm           c. kg, m and K n            d. kg, m & pa

9. Which of the following are the fundamental units involved in the unit of density? (A)
a. kg/ms²                     b. kg m²/s²                              c. g/ms²                         d. kg/m³

10. Identify the physical quantity related to the given units.
i) kg m²/s³          ii) kg m/s²
a.  (i) Power (ii) Force                                        b. (i) Pressure (ii) Density
c. (i) Force (ii) Pressure                                     d. (i) Pressure (ii) Force

11. Identify the group of fundamental units from the following.
a. metre, Kelvin ,watt and Newton
b. kilogram, Pascal , joule and watt
c. metre ,kilogram ,second and candela
d. metre, kilogram ,watt and second

12. Which of the following is the group of derived units?

  1. m, s, pa and N
    b. Pa, N, m/s and W
    c. k, m,kg and s
    d. kg, K, pa and N

 

  1. If a researcher can change the fixed amount of a variable in research that type of variable is called ……………….
  2. independent variable
    b. dependent variable
    c. control variable
    d. both a and b

14.which of the following is not the characteristic of a dependent variable?
a. it‘s value depends on the value of amount variable.
b. researchers cannot fix it’s value
c. researchers can fix its value.
d. its value depends on the value of the independent variable.

  1. The variable that is controlled bio research or during research is called …………………….

 

  1. independent variable
    b. dependent variable
    c. control variable
    d. both b and C

 

  1. Find out the group of fundamental units of power from the following.
    a. kgm²/s²                            b. kg m²/s³          c. kg m/s²            d. kg/ms²17. Which of the following units is a fundamental unit?
    a. pascal                                b. watt                 c. newton            d. kilogram

    18. Which one of the following units is a derive unit?
    a. joule                                   b. second             c. meter               d. watt

    19.  Which of the following is the correct formula for acceleration?(K)

    a.  a =                               b. a =              c. v= u+at²        d. a =

    20. Which of the following are the fundamental units involved in the unit of the

moment ?
a. kgm²/s³                            b. kgm²s                 c. kg²m²/s²       d. kgm²/s²

21. Identify the groups of fundamental units from the following.

 

  1. m², J, m, kg, A
    b. Cd, N, Pa , J, K
    c. Cd, A, mol, K, kg
    d. m, kg, Cd, A, K

 

 

Very short question answer.
22. What is scientific study?
Ans: Scientific study is the careful and organized exploration of the natural world to understand how things work.

23. What is a variable?
Ans: A variable is something that can change or vary in an experiment.

24. How many types of variables are there?
Ans: There are three types of variables: independent, dependent, controlled.

27.Define independent variables.
ans:An independent variable is a factor that you intentionally change in an experiment to see its effect.

28.Give one example of the independent variable.
ans.An example of an independent variable is changing the amount of sunlight to see how it affects plant growth

29.What is meant by a dependent variable?
ans:The dependent variable is the factor that responds to changes in the independent variable.

30.Define a controlled variable.
ans:A controlled variable is a factor that is kept constant in an experiment to ensure a fair test.

31.Write one difference between independent variable and the dependent variable.
ans:Independent variable : The independent variable ais deliberately changed .
Dependent variable: The dependent variable depends on the independent variable and it is measured or observed.

32. Give one example of a controlled variable.
ans:An example of controlled variable is keeping the temperature the same when testing how different types of soil affect plant growth.

33.Which one is the independent variable in the research question, the relation between the flow of water and rotation of the knob of the tap?
ans:In the research question about the flow of water and rotation of the knob of the tap, the independent variable is the rotation of the knob of the tap.

34.What is the fundamental unit?
ans:The fundamental units is the basic unit of measurement in the International System of units (SI) which does not depend on other units of measurement.

35.Define a derived unit .
ans:A derived unit is a unit of measurement that depends on fundamental units and is created by combining one or more fundamental units.

36.Write one difference between fundamental units and derived units.
ans:Fundamental units: The fundamental units are the basic building blocks of measurement which are independent od one another.
Derived units: The derived units depend on fundamental units and are created by combining fundamental units.

37. Write down the units of length and temperature in the SI system.
ans:In the SI system , the unit of lenght is the meter (m) , and the unit of temperature is the Kelvin (K).

38. Write down the SI units of density and moment in the SI system.
ans:In the SI system , the unit of density is kilograms per cubic meter (kg/m³) and the unit of moment is newton-meter(N.m.)

39.Which are the fundamental units involved in the unit of power ?
ans:The fundamental units involved in the unit of power are the meter (m) ,kilogram (kg) , and second (s).

40.Why is the unit of force called a derived unit?
ans:The unit of force (N) is called a derived unit because it depends on fundamental units kilogram, meter, and second (N=kg.m/s²).

41.What are the fundamental units involved in the unit of the pressure?
ans:The fundamental units involved in the unit of pressure are the meter (m) , kilogram (kg) , and second (s).

42.We should control some variables while doing experiments, why ?
ans:We should control some variables while doing experiments to ensure that the changes we observe are due to the independent variable and not influenced by other factors or variables.

43. Why is the unit of length called a fundamental unit ?
ans:The unit of lenght , i.e ..,metre (m) is independent of other units of measurement.So , it is called a fundamental unit or basic unit.

44. Give any two example of fundamental unit.
ans: Any two example of fundamental unit:
i) Kelvin
ii) Kilogram

45.Why is the unit of speed called a derived unit ?
ans: The unit of speed depends on two fundamental units i.e…metre (m) and second (s) .So, the unit of speed is called a derived unit.

47.Why is joule called a derived unit?
ans:The unit joule (J) depends on theee fundamental units,i.e..,kilogram, metre and second.So ,the unit joule is called a derived unit.

Short answer questions

48.What is meant by scientific learning?Write with an example.
ans: Scientific learning is about discovering how things work by asking questions, experimenting and gathering evidence.For example , when we want to know if plants grow better with more sunlight, we set up an experiment with different levels of sunlight and observe how the plants grow.

49.What is meant by an independent variable?Write with one example.
ans:An independent variable is a variable that a researcher deliberately changes in an experiment to see how it affects the dependent variable.For example , if we want to test how the amount of water affects plant growth, the amount of water given to the plant is the independent variable.

50.What is meant by a dependent variable? Write with an example.
ans: A dependent variable is the change that a researcher measures or observes in an experiment,and it responds to changes in the independent variable.In the plant growth experiment, the growth in height of the plants is the dependent variable because it depends on the amount of water given to plants.

54.Write down the SI unit of the given physical quantities.
a) Acceleration                   b) Luminous intensity
c) Pressure                          d) Temperature
ans: SI units for the given physical quantities are:
a) Acceleration -meter per second square (m/s²)
b) Luminous intensity -candela(cd)
c) Pressure -pascal (pa)
d) Temperature – kelvin (k)

55.Identify the fundamental units involved in the given physical quantities.
ans:The fundamental units involved in the given physical quantities are:
a) Speed – meter per second (m/s) involves meter and second.
b) Power – watt (W) involves kilogram (kg) , meter (m) and second (s).

56.identify the fundamental units involve in the given physical quantities.
a) Workdone                         b) Moment
ans: The fundamental units involved in the given physical quantities are:
a) Work done – joule(J) involves kilogram (kg), meter(m) and second(s).
b) Moment – newton-meter (N.m) involves kilogram (kg) , meter(m) and second (s).

57.Identify the fundamental units involved in the given physical quantities.
a) Density                              b) Energy
ans: The fundamental units involved in the given physical quantities are:
a) Density – kilogram per cubic meter (kg/m³) involves kilogram (kg) and meter(m).
b) Energy – joule (J) involves kilogram (kg) , meter (m) and second (s).

58.Write any two factors that should be remembered related to variables.
ans: The two factors that should be remembered related to variables are as follows:
i) there should be only one independent variable in an experiment or research work.
ii)there should be only one dependent variable in an experiment order research work.

59.In a research question, the relationship between the amount of current produced in a solenoid and Magnetism, find out the dependent and independent variables.
ans:In the Research question about the amount of current produce in a solenoid and Magnetism, the independent variable is magnetism and the dependent variable is the amount of current.

60. In a research question, the effect of heat on the solubility of copper sulphate , find out independent and controlled variables.
ans: In the research question about the effect of heat on the solubility of copper sulphate, the independent variable is heat , and the controlled variables could include the amount of copper sulphate, the type of container, and the temperature of the solution.

62.Give reasons:

a) The unit of time is called a fundamental unit.
ans: The unit of time is independent of other units of measurement. So, the unit of time is called a fundamental unit.

b) The unit of force is called a derived unit , why ?
ans: The unit of force , i.e., newton depends on three fundamental units, i.e., kg, m and s. So , it is called a derived unit.

63.Write down the independent and dependent variable in the experiment that is conducted to find out the effect of sunlight on the growth of plants .
ans: In the guven experiment:
Independent variable: Amount of sunlight received by plants everyday.
Dependent variable: Growth of plants.

SECTION D

Long answer questions.

64. What is meant by variables of scientific research? Explain their types with examples.
ans: Variables in scientific research are factors or characteristics that can change or vary and are studied to understand their effects on a particular phenomenon.These variables are crucial in experiments and observational studies as they allow reserchers to investigate relationships, make predictions, and draw conclusions. There are three types of variables.They are : Independent, dependent and controlled.

a) Independent variable:This is the variable that the researcher  deliberately changes are manipulates to see its impact on the dependent variable . For example , in study examination of blood pressure , the Independent variables would be the dose of the medication.

b) Dependent variable: The dependent variable is what the researcher measures or observes as a response to changes in the independent variables .In the medication study mentioned earlier, the dependent variables would be the blood pressure of the participants.

c) Controlled variables: These are factors that the research or keeps constant throughout the experiment to ensure that the changes in the dependent variable add due to the independent variables manipulation. In the meditation study ,control variables might include the participants age, gender, and health conditions.

65.Write down the types of physical quantities to which given units belong.
a) kilogram        b) pascal       c) newton         d) second

ans: a) kilogram: The unit “kilogram” belongs to the physical quantity of mass.This is because a kilogram is a measure of the amount of matter in an object, and mass is a fundamental physical quantity.

b) pascal : The unit “pascal” belongs to the physical quantity of pressure.This is because the pascal (Pa) is a unit of pressure, which is defined as force per unit area. Pressure is a derived physical quantity.

c) newton: The unit “newton” belongs to the physical quantity of force. This is because the newton(N) is the unit used to measure force , and the force is a fundamental physical quantity.

d) second: The unit “second”belongs to the physical quantity of time.The second (s) is a fundamental unit of time.It is a fundamental physical quantity.

66. Give a reasons.

a) The unit of mass is called a fundamental unit and that of force is called a derived unit.
ans: The unit of mass is called a fundamental unit because mass is consi6a fundamental physical quantity as it does not depend on other physical quantities.On the other hand, the unit of force called a derived unit because force is derived from fundamental quantities, specifically mass , length and time.

b) Variables are very important for scientific learning.
ans: Variables are very important for scientific learning because they allow reserchers to investigate understand and explain natural phenomena. Here are some reasons why variables are crucial in scientific learning:
i) Variables help researcher identify cause-and-effect relationships by manipulating independent variable and observing the resulting changes in dependent variables.

ii) They enable researcher to make predictions and test hypotheses, which are fundamental to the scientific method.

iii) Variables help in designing controlled experiments by keeping certain factors constant (controlled variable) to isolate yhe effects of the variables of interest.

67.Find out the fundamental units involved in the units of the given physical quantities.
a) Velocity            b) Volume            c) Work              d) Power

ans: a. Velocity
Formula: Velocity=displacement/time taken
Fundamental units=metre (m) / second (s)
=m/s
So, the fundamental units involve in the units of velocity are m and s .

b. Volume
Formula:Volume= length × breadth × height
Fundamental units= metre(m) × metre(m) × metre(m)
= m × m × m
So, the fundamental units involved in the units of velocity are m, m and m.

c. Work
Formula : Work = force × displacement
= mass × acceleration × displacement
Fundamental units = kg × (m/s²) × m
So, the fundamental units involved in the units of velocity are kg, m and s .

d. Power
Formula : Power (P) = work done / time taken
= force × displacement / time taken
= mass × acceleration × displacement/ time    taken
Fundamental units = kg × (m/s²) × m/s
So, the fundamental units involved in the units of velocity are kg , m and s.

68. Write down four things that should be considered about variables while doing scientific research.
ans: i) There should be only one independent variable in an experiment or a research work.
ii) There should be only one dependent variable in an experiment or a research work.
iii) The variables expect to independent variable and dependent variables will be controlled.
iv) While presenting the relation between two variables in a graph, the dependent variables will be plotted on the Y- axis and independent variables should be plot it on the X-axis due to this the dependent variable is called a vertical variable and the independent variable is called a horizontal variable.

71.Why is unit as analysis of equations done in physics ? Clarify with an example.
ans: Unit – wise analysis of equations is done in physics to check the consistency of units and to ensure that equations are dimensionally correct. In other words ,it helps verify that the units on both sides of an equation are compatible, which is important for the validity of physical laws and equations. This analysis helps in finding errors , confirming the correctness of equations and ensuring that the physical quantities involved in an equation are used consistently.
Here is an example to illustrate the importance of unit-wise analysis:
v= d/t
Now, if we perform a unit-wise analysis:
i) The unit of distance (d) is measured in meters (m) .
ii) The unit of time (t) is measured in seconds (s) .
Therefore, the unit of velocity (v) should be meter per second (m/s).
If , during the calculation, we mistakenly used distance in meter but time in minute (instead of second ) , the equation would look like this :
v=d(in meters)/t (in minutes)
Without unit-wise analysis, this mistake might go unnoticed, and we would end up with a velocity in meter per minute , which is not a standard unit of velocity.
By performing unit-wise analysis, we can catch such errors and inconsitencies , ensuring that our equations are similar correct and our calculations are physically meaningful. It is an essential step in the scientific method to maintain the integrity and accu6of equations and laws of physics.

73.Rama wanted to test the effect of fertilizer on the growth of plants.
a) What is the independent variable in her experiment (test)?Why?
b) What is the controlled variable in her experiment? Why ?
c) What is the dependent variable in her experiment?

ans: In Rama’s experiment to test the effect of fertilizer on plant growth:

  1. The independent variable is the “fertilizer”. It is the variable that
    Rama intentionally changes or manipulates in her experiment to
    see its effect on plant growth. By varying the type or amount of
    fertilizer, she can observe how it influences the plants’ growth.
  2. Controlled variables in her experiment are factors that Rama keeps constant to ensure that the changes in plant growth are due to the fertilizer and not influenced by other factors. Controlled variables might include things like the type of soil used, the amount of water given to the plants, the amount of sunlight they receive, and the temperature in which they are grown. These variables are controlled to isolate the effect of fertilizer.
  3. The dependent variable in her experiment is the ‘’plant growth.’’ It is what Rama is measuring or observing as a response to change in the independent variable. She may measure plant growth by recording factors like plant height, number of leaves, or overall health and size of the plants. The dependent variable allows her to assess whether the fertilizer has a significant impact on the plants growth.

 

 

 

By Ghising

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