Class 10 Science SEE Guide | Unit - 1 Scientific Learning Guide 2080

Class 10 Science SEE Guide

Unit - 1

Scientific Learning Guide

( नेपालीमा उत्तर तल दिइएको छ )

Exercise

1. Choose the correct options for the following questions.

a. Which of the following is a fundamental unit?

i, newton

ii. pascal

iii. kilogram

iv. joule

Answer 👉 iii. kilogram

b. Which of the following physical quantities has the unit ms-1?

i. acceleration

ii. velocity

iii. force

iv. density

Answer 👉 ii. velocity

c. Which of the following is a derived unit?

i. candela

ii. ampere

iii. joule

iv. kelvin

Answer 👉 iii. joule

d. Which of the following units denote Newton?

i, kgms-2

ii. kgm2s-2

iii. kgm-s-2

iv. kgms-1

Answer 👉 i, kgms-2

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2. Give reason:

a. Joule is the derived unit of work.

Answer 👉 Joule is the derived unit of work because work is defined as the product of force and displacement, and the unit of force is newton (N) and the unit of displacement is meter (m). The product of newton and meter gives us the unit of work, which is joule (J).

b. Some variables should be controlled while performing an experiment.

Answer 👉 Some variables should be controlled while performing an experiment to ensure that the observed changes or outcomes are due to the specific variables being investigated and not influenced by other factors. By controlling certain variables, scientists can isolate the effects of the variables they are interested in studying and minimize the influence of confounding factors. This helps to establish a cause-and-effect relationship between the variables under investigation.

c. v=ut is not a valid relation.

Answer 👉 v := ut is not a valid relation because it is missing the necessary mathematical operator. The equal sign (=) is commonly used to indicate equality or assignment of a value, but in this case, it seems that a mathematical operation is intended. If the relation is meant to represent an equation for velocity (v) in terms of initial velocity (u), time (t), and some operation, such as addition or multiplication, the appropriate mathematical symbol needs to be used (e.g., v = u + at or v = u * t).

3. Differentiate between:

a. Independent variable and dependent variable

Answer 👉

Independent variable: The independent variable is the variable that is intentionally manipulated or controlled by the experimenter in an experiment. It is the presumed cause or input in a study. Changes in the independent variable are believed to influence or cause changes in the dependent variable. The independent variable is typically plotted on the x-axis of a graph.

Dependent variable: The dependent variable is the variable that is measured or observed in response to changes in the independent variable. It is the outcome or result that is measured and studied in an experiment. The dependent variable is expected to be influenced by the changes in the independent variable. The dependent variable is typically plotted on the y-axis of a graph.

b. Fundamental unit and derived unit

Answer 👉

Fundamental unit: A fundamental unit is a unit of measurement that is considered basic, fundamental, and independent. Fundamental units are used to express primary physical quantities, and they are not derived from any other units. Examples of fundamental units include the meter (m) for length, the kilogram (kg) for mass, and the second (s) for time. These fundamental units form the basis of the measurement system.

Derived unit: A derived unit is a unit of measurement that is derived from fundamental units through mathematical combinations or equations. Derived units are used to express derived or composite physical quantities. For example, the unit of speed, meters per second (m/s), is a derived unit because it is obtained by dividing the unit of distance (meter) by the unit of time (second). Other examples of derived units include the newton (N) for force, which is derived from the fundamental units of kilogram, meter, and second, and the joule (J) for energy, which is derived from the fundamental units of kilogram, meter, and second as well.

4. Answer the following questions:

a. What is a unit?

Answer 👉 A unit is a standardized measurement that is used to quantify a physical quantity. It provides a reference for comparing and expressing measurements in a consistent and universally understood manner. Units are typically defined based on agreed-upon standards and conventions.

b, Write the SI units of mass, temperature, energy, and density.

Answer 👉 The SI units (International System of Units) for the given physical quantities are:

Mass: kilogram (kg)
Temperature: Kelvin (K)
Energy: Joule (J)
Density: kilogram per cubic meter (kg/m³)

c. How is the validity of an equation checked? Write an example.

Answer 👉 The validity of an equation is checked by ensuring that the units on both sides of the equation are consistent and compatible. The units of each term in the equation must match on both sides. One common approach is to analyze the dimensions and units of each variable involved in the equation.

Example: Let's consider the equation for velocity, v = d/t, where v represents velocity, d represents distance, and t represents time. To check the validity of this equation, we analyze the units:

Unit of v (velocity) = Unit of d (distance) / Unit of t (time)

The unit of velocity is typically meters per second (m/s), the unit of distance is meters (m), and the unit of time is seconds (s). Therefore, the units on both sides of the equation are consistent, and the equation is valid.

d. Mention the fundamental units involved in the unit of pressure.

Answer 👉 The unit of pressure involves the fundamental units of force and area. Therefore, the fundamental units involved in the unit of pressure (P) are:

Force (F): kilogram (kg), meter (m), second (s)
Area (A): meter (m), meter (m)

e. Find out the fundamental units involved in the given derived unit,

i. newton (N)

ii. watt (W)

iii. joule (J)

iv. pascal (Pa)

Answer 👉 The fundamental units involved in the given derived units are:

i. Newton (N): kilogram (kg), meter (m), second (s)
ii. Watt (W): kilogram (kg), meter (m), second (s)
iii. Joule (J): kilogram (kg), meter (m), second (s)
iv. Pascal (Pa): kilogram (kg), meter (m), second (s)

f. Nivaclaimed that an alternative formula for power is P=mv? and the formula of pressure; P=mv/A. Check the validity of given formulae by the analysis of units.

Answer 👉 Let's analyze the validity of the given formulas by checking the consistency of units:

P = mv (power formula)

Unit of P (power) = Unit of m (mass) * Unit of v (velocity)

The unit of power is typically watt (W), the unit of mass is kilogram (kg), and the unit of velocity is meters per second (m/s). Therefore, the units on both sides of the equation are consistent, and the formula is valid.

P = mv/A (pressure formula)

Unit of P (pressure) = Unit of m (mass) * Unit of v (velocity) / Unit of A (area)

The unit of pressure is typically pascal (Pa), the unit of mass is kilogram (kg), the unit of velocity is meters per second (m/s), and the unit of area is square meters (m²). Therefore, the units on both sides of the equation are consistent, and the formula is valid.

g. Describe the independent variable, dependent variable and controlled variable with a suitable example of each.

Answer 👉 Independent variable: The independent variable is the variable that is intentionally manipulated or changed by the experimenter. It is the presumed cause or input in a study.

Dependent variable: The dependent variable is the variable that is measured or observed in response to changes in the independent variable. It is the outcome or result that is measured and studied in an experiment.

Controlled variable: Controlled variables are the variables that are kept constant or controlled throughout the experiment to ensure that they do not influence the outcome.

Example: Let's consider an experiment studying the effect of fertilizer on plant growth:

Independent variable: The type or amount of fertilizer applied to the plants.
Dependent variable: The height or growth rate of the plants.

h. Karma connected a dry cell to a bulb using a few pieces of wire and lit the bulb. He was curious to know how the thick- ness of the used wire affects the life span of a dry cell. In this test or experiment, find out the independent variable. dependent variable and controlled variable.

Answer 👉 In Karma's experiment:

Independent variable: The thickness of the used wire. Karma intentionally changes the thickness of the wire to see how it affects the life span of the dry cell.
Dependent variable: The life span of the dry cell. This is the variable that Karma is interested in measuring and observing as a response to the changes in the thickness of the wire.
Controlled variables: Karma needs to control other factors that could potentially influence the life span of the dry cell. These controlled variables may include the type and brand of the dry cell, the type of bulb, the length and material of the wire (except for the thickness), the ambient temperature, and the duration of the experiment. By keeping these variables constant, Karma can isolate the effect of the wire thickness on the life span of the dry cell.

i. Chandani wanted to investigate the effects of substances mixed with the soil on plant growth. She decided to mix lime, urea fertilizer, common salt, and compost manure in the soil. Then she brought a bucket of soil from a nearby field and sieved it. She put that soil equally into 12 uniform- sized pots. Then she mixed two spoons of salt in every three pots, two spoons of urea fertilizer in each of the next three pots, two spoons of table salt in each of the next three pots, and finally, two spoons of compost fertilizer in each of the remaining three pots.She then planted similar seeds of the same plant in every pot and placed them all in a sunny place in the house. She watered all the pots every day. After the plants grew, she measured the height of each plant daily and kept a record.

i, Identify the independent variable, dependent variable and controlled variable in Chandani's experiment.

Answer 👉 In Chandani's experiment:

Independent variable: The substances mixed with the soil (lime, urea fertilizer, common salt, compost manure). Chandani intentionally chooses and varies the type of substances mixed in the soil to observe their effects on plant growth.

Dependent variable: Plant growth, specifically the height of the plants. Chandani measures the height of each plant daily and records it as an indication of their growth.

Controlled variables: Chandani needs to control other factors that could potentially affect plant growth. These controlled variables may include the type of plant seeds used, the amount of soil in each pot, the amount of water provided, the exposure to sunlight, the size and type of pots, the location where the pots are placed, and the duration of the experiment. By controlling these variables, Chandani aims to isolate and observe the specific effects of the substances mixed with the soil on plant growth.

ii. Why did Chandani use 3 pots for each experiment?

Answer 👉 Chandani uses 3 pots for each experiment to increase the reliability and validity of her results. By having multiple pots for each substance, she can compare the average growth of the plants within each group and observe any consistent trends or patterns. This helps to reduce the impact of random variations or outliers in individual pots, providing a more representative and robust analysis of the effects of different substances on plant growth. Additionally, using multiple pots allows Chandani to account for any differences between the pots themselves, such as variations in soil composition or placement within the experimental setup.

j. Subodh wanted to find out how the colour of an object affects its ability to hold heat. For that, he took four conical flasks and coated the first flask with black coloured enamel. the second with white enamel, the third with green enamel and the fourth with red enamel. Then, he filled all the flasks with water, closed the mouth of each flask tightly with cork and then kept them in the sun. After some time he measured the temperature of water in each flask with the help of a thermometer and noted the readings.

Identify the independent variable and dependent variable in Subodh’s experiment. Which variables should be controlled by Subodh?

Answer 👉 In Subodh's experiment:

Independent variable: The color of the enamel coating on the conical flasks (black, white, green, red). Subodh intentionally changes the color of the flask's coating to observe its effect on heat retention.

Dependent variable: The temperature of the water in each flask. Subodh measures the temperature of the water in each flask using a thermometer and records the readings as an indication of heat retention.

Controlled variables: Subodh needs to control other factors that could potentially influence heat retention. These controlled variables may include the type and size of the conical flasks, the volume of water in each flask, the material and thickness of the flask walls, the time of exposure to the sun, the intensity of sunlight, and the ambient temperature. By keeping these variables constant, Subodh aims to isolate and observe the specific effects of the flask's color on heat retention.

k. Manisha wanted to test the eating habits of her dog. She decided to study how the amount of food and the time of giving food affects the speed at which the dog ate. What is wrong with the design of Manisha's experiment and how can she correct it?

Answer 👉 The issue with Manisha's experiment design is that she is testing two independent variables simultaneously (amount of food and time of giving food) without controlling one variable while studying the other. This can lead to confounding variables and difficulty in attributing the observed effects to specific factors.

To correct the design of Manisha's experiment, she should conduct separate experiments, focusing on one variable at a time while keeping the other constant. For example, in one experiment, she can vary the amount of food given to the dog while keeping the time of giving food constant. In another experiment, she can vary the time of giving food while keeping the amount of food constant. This approach will allow her to systematically examine the individual effects of each independent variable on the dog's eating speed and draw more reliable conclusions.

l. Prove that: Unit of electric resistance ohm = kgm2s-3A-2

Answer 👉 To prove that the unit of electric resistance, ohm (Ω), is equivalent to kgm^2s^-3A^-2, we can break down the units of each term in the equation.

The unit of electric resistance, ohm (Ω), is defined as the ratio of voltage (V) to current (A). Mathematically, Ohm's law states that resistance (R) is equal to voltage divided by current (R = V/I).

Let's break down the units on both sides of the equation:

On the left side:

Resistance (R) is measured in ohms (Ω).

On the right side:

Voltage (V) is measured in volts (V), which is equivalent to kgm^2s^-3A^-1.

Current (I) is measured in amperes (A).

Now, let's substitute the units into Ohm's law:

Ω = (kgm^2s^-3A^-1) / A

Simplifying the equation:

Ω = kgm^2s^-3A^-2

Therefore, we have proven that the unit of electric resistance, ohm (Ω), is equivalent to kgm^2s^-3A^-2.

पाठ १ : वैज्ञानिक अध्ययन

1. तलका प्रश्नको सही विकल्प छनोट गर्नुहोस् :

(क) तलका मध्ये कुन आधारभूत एकाइ हो ?

(अ) न्युटन

(आ) पास्कल

(इ) किलोग्राम

(ई) जुल

Answer 👉 (इ) किलोग्राम

(ख) दिइएका मध्ये कुन भौतिक परिमाणको एकाइ ms-1' हुन्छ ?

(अ) प्रवेग

(आ) गति

(इ) बल

(ई) घनत्व

Answer 👉 (आ) गति

(ग) तलका मध्ये कुन तत्जन्य एकाइ हो ?

(अ) क्यान्डेला

(आ) एम्पियर

(इ) जुल

(ई) केल्भिन

Answer 👉 (इ) जुल

(घ) तलका मध्ये कुन आधारभूत एकाइको समूहले बलको एकाइ न्युटन (N) तत्जन्य एकाइ जनाउँछ ?

(i) kgms-2

(ii) kgm2s-2

(iii) kgm-2s-2

(iv) kgms-1

Answer 👉 (i) kgms-2

2. कारण दिनुहोस् ।

(क) कार्यको एकाइ जुल तत्जन्य एकाइ हो ।

Answer 👉 कार्यको एकाई एक जुल तत्जन्य एकाई हो किनकी जुललाई अब विद्युत् चुम्बकत्व एकाईको आधारमा परिभाषित गरिएको थिएन तर यसको सट्टा 1 मिनेटको दुरीमा बलको एक एकाई दुरा गरिएको कार्यको एकाईको रुपमा परिभाषित गरिएको थियो ।

(ख) प्रयोग गर्दा केही चरहरुलाई नियन्त्रण गर्नुपर्छ ।

Answer 👉 प्रयोग गर्दा केही चरहरुलाई नियन्त्रण गर्नुपर्छ किनकी असुन्धानको अवधिभर तिनीहरुमा पाउने पानी, मन हावा सबैमा एक रुपता कायम गर्नुपर्छ। त्यसैले विरुवा सुरुको अबस्थामा तिनीलाई दिने पानी, मल, आदिको मात्रा नियंत्रित चर हुन्। त्यसैले यो प्रयोग गर्दा केही चरहरुलाई नियन्त्रण गर्नुपर्छ ।

(ग) V2 = ut हुँदैन ।

Answer 👉 "V2=ut" यसले बाटोका आरम्भिक वेग र समयको न्यूनतम गणना गर्दछ। "V" छोटो "वेग" हो, "u" छोटो "आरम्भिक वेग" हो, र "1" छोटो "समय" हो । यसले कहिल्यै "V2=ut" हुँदैन ।

3. फरक लेख्नुहोस् :

क) स्वतन्त्र र आश्रित चर

स्वतन्त्र चर :

- प्रयोगकर्ताले मान निर्धारण गर्न सक्ने चरलाई स्वतन्त्र चर भनिन्छ ।

- चरहरूको सम्बन्धलाई गणितीय समीकरणमा लेख्दा प्राय: स्वतन्त्र चरलाई समीकरणको दायाँपट्टि राखिन्छ ।

आश्रित चर :

- प्रयोगकर्ताले प्रत्यक्ष मान निर्धारण गर्न मिल्दैन त्यस्तो चारलाई आश्रित चर भनिन्छ ।

- चरहरूको सम्बन्धलाई गणितीय समीकरणमा लेख्दा प्राय: आश्रित चरलाई समीकरणको बायाँपट्टि राखिन्छ ।

ख) आधारभूत र तत्जन्य एकाई

आधारभूत एकाई :

- अरु एकाइमा निर्भर नरहने र अरु एकाइमा टुक्र्याउन नसकिने एकाइलाई आधारभुत एकाई भनिन्छ ।

- SI प्रणाली अनुसार सात वटा मात्र आधारभूत एकाइहरू छन् ।

- तत्जन्य एकाइको मद्दतले आधारभूत एकाइहरू बनाउन सकिँदैन ।

- जस्तैः लम्बाइ, पिण्ड, समय आदि आधारभूत एकाइहरू हुन् ।

तत्जन्य एकाई :

- दुई वा दुईभन्दा बढी आधारभूत एकाइको संयोजनबाट बनेका एकाइलाई तत्जन्य भनिन्छ ।

- SI प्रणाली अनुसार सात भन्दा बढी तत्जन्य एकाइहरू छन् ।

- आधारभूत एकाइहरुको मद्दतले तत्जन्य एकाइहरु बनाउन सकिन्छ ।

- जस्तैः गति, बल, कार्य आदि तत्जन्य एकाइहरू हुन् ।

4. दिएका प्रश्नको उत्तर दिनुहोस् :

क) एकाइ भनेको के हो ?

Answer 👉 कुनै पनि भौतिक परिमाण नाप्नका लागि बनाइएको Standard परिमाणलाई एकाइ भनिन्छ । जस्तै: मिटर, किलोग्राम, सेकेन्ड आदि एकाइहरू हुन् ।

ख) पिण्ड, तापक्रम, शक्ति र घनत्वका एकाइहरु लेख्नुहोस् ।

> Answer 👉 पिण्ड = किलोग्राम ( Kg)

> तापक्रम = केल्भिन (K)

> शक्ति = जुल (J)

> घनत्व - किलोग्राम प्रतिघनमिटर (kg/m 3 )

ग) समीकरणमा एकाईको एकरुपता कसरी जाँच गरिन्छ ? उदाहरणसहित प्रष्ट पार्नुहोस् ।

Answer 👉 वैज्ञानिक अध्ययन बाट निष्कर्षका रूपमा विभिन्न सुत्र र समीकरण प्राप्त हुन्छन् यस्ता सूत्र वा समीकरणको एकरुपता र वैधता त्यसमा सम्मलित भौतिक परिमाणका एकाईको विश्लेषणबाट जाँच गरिन्छ । उदाहरणको लागि s=vxt समीकरणको एकाइगत विश्लेषण गर्दा बायाँपट्टिको परिमाणको आधारभुत m हुन्छ भने दाँयापट्टीको परिमाण आधारभुत एकाई पनि ms - 1+ = m नै हुन्छ यसरी समीकरणहरूको एकरुपता जाँच गर्न सकिन्छ ।

घ) चापको एकाइमा रहेका आधारभूत एकाइहरू लेख्नुहोस् ।

Answer 👉 चापको एकाइमा रहेका आधारभूत एकाइहरू किलोग्राम मिटर र सेकेन्ड (Kg/ms2) हुन्।

ङ) दिएको तत्जन्य एकाइमा प्रयोग भएका आधारभुत एकाई पत्ता लगाउनुहोस् :

Answer 👉

अ) न्युटन (N)

बलको परिभाषाअनुसार, F = ma हुन्छ ।

पिण्ड(m) को एकाई kg र प्रवेगको एकाइ ms-2 हुन्छ।

त्यसैले बलको एकाइ (N) = kgms - 2 हुन्छ । तसर्थ किलोग्राम, मिटर र सेकेन्ड जस्ता आधारभूत एकाइहरू मिलेर बलको एकाइ N बनेको हुन्छ ।

आ) वाट (w)

.:. एकाइमा प्रयोग भएका आधारभुत एकाई kgm2/s3 हुन् ।

इ) जुल(1)

.:. एकाइमा प्रयोग भएका आधारभुत एकाई kgm2/s2 हुन् ।

ई) पास्कल (P)

.:. एकाइमा प्रयोग भएका आधारभुत एकाई kg/ms 2 हुन् ।

छ) स्वतन्त्र चर, आश्रित चर र नियन्त्रि चरलाई उदाहरणसहित व्याख्या गर्नुहोस् ।

Answer 👉

- स्वतन्त्र चर : प्रयोगकर्ताले मान निर्धारण गर्न सक्ने चरलाई स्वतन्त्र चर भनिन्छ । जस्तै : गर्दा रवर व्यान्डको तत्काइ स्वतन्त्र चर हुन् ।

- आश्रित चर : प्रयोगकर्ता प्रत्यक्ष मान निर्धारण गर्न नसक्ने चरलाई आश्रित चर भनिन्छ। जस्तैः गुलिको प्रयोग गर्दा कागजको गोलीले पार गर्ने दुरी आश्रित चर हुन् ।

- नियन्त्रि चर : प्रयोग गर्दा नियन्त्रणमा लिनु पर्ने चरलाई नियन्त्रित चर भनिन्छ । जस्तै : गुलेलिको प्रयोग गर्दा रवर ब्यान्डको मोटाइ र कागजको गोलीको साइज नियन्त्रित चर हुन् ।

(ज) कर्माले केही तारका टुक्रा प्रयोग गरेर एउटा ड्राइसेललाई चिममा जोडी बत्ती बाले उनलाई प्रयोग गरिएका तारको 1 मोटाइले ड्राइसेलको आयुलाई कसरी असर गर्छ भनेर जान्न मन लाग्यो । यसबारे उनले गर्ने परीक्षणमा स्वतन्त्र चर, आश्रित चर र नियन्त्रित चर छुट्याउनुहोस् ।

Answer 👉

स्वतन्त्र चर = तारका टुक्रा

आश्रित चर = एउटा ड्राइसेललाई चिममा जोडी बत्ती बाल्नु

नियन्त्रित चर = तारको मोटाइ र ड्राइसेलको आयु

(झ) चांदनीलाई माटामा मिसिएका वस्तुले बिरुवाको बुद्धिमा के असर पार्छ भनी अनुसन्धान गर्न मन लाग्यो । उनले माटामा चुन युरिया मल खाने नुन र कम्पोस्ट मलको असर जांच्ने निधो गरिन् । त्यसपछि बारीबाट एक बाल्टी राम्रो माटो ल्याइन् र त्यसलाई राम्ररी चालिन् । त्यो माटालाई 12 ओटा एकैनासे गमलामा बराबर राखिन् । तीनओटा गमलामा दुई दुई चम्चा चुन अर्को तीनओटा गमलामा दुई दुई चम्चा युरिया मल, अर्को तीनओटा गमलामा दुई दुई चम्चा खाने नुन र अर्को तीनओटा गमलामा दुई दुई चम्चा कम्पोस्ट मल हालिन् । त्यसपछि सबै गमलामा एकै नासका बिउ रोपेर सबैलाई घरकोपेटीको घाम लाग्ने ठाउँमा राखिन् । प्रत्येक दिन सबै गमलामा पानी हालिन र बिरुवा उमेपछि दैनिक प्रत्येक बिरुवाको उचाइ नापेर अभिलेख राखिन् ।

(अ) चांदनीको प्रयोगमा स्वतन्त्र चर, आश्रित घर र नियन्त्रित चर छुट्याउनुहोस् ।

Answer 👉

स्वतन्त्र चर = माटामा चुन युरिया मल खाने नुन र कम्पोस्ट मलको प्रयोग गर्नु

आश्रित चर = सबैलाई घरकोपेटीको घाम लाग्ने ठाउँमा राखिन्

नियन्त्रित चर = प्रत्येक दिन सबै गमलामा पानी हालिन्

(आ) चाँदनीले किन हरेक मिसावटका लागि तीन तीनओटा गमला प्रयोग गरेकी होलिन् ?

Answer 👉 चांदनीले हरेक मिसावटका लागि तीन तीनओटा गमला प्रयोग गर्दछ भनेर जनाएका छन् किनकि त्यसले बिरुवा, युरिया मल, खाने नुन र कम्पोस्ट मलका असरलाई अलग-अलग गमलामा नोट गर्दछ र बिरुवा उमेका बादले प्रत्येक बिरुवाको उचाइ नाप्ने गरी अभिलेख राख्न पर्छ । यसले मूल्यांकनलाई सही गर्दछ र निष्पक्ष परिणाम प्राप्त गर्न मद्दत गर्दछ ।

ञ) सुबोधले वस्तुको रङले उसको ताप धारण गर्न सक्ने क्षमतालाई कसरी फरक पार्ख भनी पत्ता लगाउन चाहे । त्यसका लागि उनले चारओटा कोनिकल फ्लाक्स लिए र पहिलोमा कालो इनामेल, दोस्रोमा सेतो इनामेल, तेस्रोमा हरियो इनामेल र चौथोमा रातो इनामेल पोते । त्यसपछि प्रत्येक फ्लाक्समा पानी भरेर तिनीहरूको मुख कर्कले बन्द गरी घाममा राखे । केही समयपछि थर्मोमिटरको सहायताले प्रत्येक फ्लाक्सको पानीको तापक्रम नापे र टिपोट गरे ।

(अ) सुबोधको यस प्रयोगमा स्वतन्त्र चर र आश्रित चर छुट्याउनुहोस् । साथै सुबोधले कुन कुन चरलाई नियन्त्रण गर्नु पर्ला, लेख्नुहोस् ।

Answer 👉

स्वतन्त्र चर = कोनिकलफ्लाक्स बाट इनामेल पोते

आश्रित चर = थर्मोमिटरको सहायताले फ्लाक्सक तापक्रम नापे र टिपोट गरे

नियन्त्रित चर = फ्लाक्सकलाई घाममा राखे

फेरी, कोनिकलफ्लाक्स बाट इनामेल पोत्नु र फ्लाक्सकलाई घाममा राख्नु नियन्त्रित चर हुन् ।

(ट) मनिषालाई आफ्नो कुकुरको खाना खाने तरिकासम्बन्धी परीक्षण गर्न मन लाग्यो । उनले खानाको मात्रा र खाना दिने समयले कुकुरले खाना खाने गतिलाई कसरी फरक पार्छ भनी अध्ययन गर्ने विचार गरिन् । मनिषाको यो प्रयोगको ढाँचामा के गल्ती छ र त्यसलाई उनले कसरी सुधार्न सक्छिन् ?

Answer 👉 मनीषले यो प्रयोग गर्दा ढाँचामा (खानाको मात्रा, खाना दिने समयले र कुकुरले खाना खाने गति) गल्ती गरेछ । उनले त्यसलाई क्रमशःरुपमा (खानाको मात्रा, कुकुरले खाना खाने गति र खाना दिने समय) लेख्दा ठिक हुन्थ्यो ।