SEE Science Solution 2075 Province-1
SEE 2075(2019) RE-111'AP'
Compulsory Science
Answer all the questions:-
Group"A"
1. Write short answers of the following questions.
15x1=15
a. What is the value of acceleration due to gravity at the pole of the earth?
The value of acceleration due to gravity at the pole of the earth is 9.83 m/s².
That source of energy which can be used instead of non-renewable source of energy is called alternative source of energy.
Converging lens is defined as the lense which converges a parallel beam of light coming from infinity fallen upon its surface to a point.
Transformer is a device which converts a high voltage into low voltage or vice-versa.
Neutral salt is defined as salt which pH value is 7.
Haematite and Magnetite are two ores of iron.
The general formula of alkene is C₂H₂n.
Spread of Water-borne disease and adverse effect on aquatic life and agriculture are two effects of water pollution.
2.
The object has more weight in Biratnagar. This is because acceleration due to gravity in Biratnagar is higher than Kathmandu.
3.
Two reasons for which hydro power should be given more priority rather than fossil fuel are:-
Economic:- Hydropower is Nepal's own potential where it has to export fossil fuels from other nations.
Ecology:- Fossil fuel emits carbon and degrades surrounding while hydropower has no such adverse effect.
4.
The egg kept in beaker containing pure water sinks while the egg kept in beaker containing saturated salt solution floats. This is so because pure water has lower density the egg while saturated salt solution has higher density than the egg.
5.
Reasons for using nichrome wire in electric heater are:-
(i) Nichrome is resistant to air corrosion at high temperature.
(ii) Nichrome has melting point of 1400 ºC.
6.
Two characteristics of modern periodic table are:-
7.
Aluminium reacts with dilute hydrochloric acid and form Aluminium chloride(AlCl₃) and hydrogen.
8.
Glycerol is a trihydric alcohol. It is formed by replacement of three H atoms from propane by three hydroxyl(OH) functional group.
Uses of ethyl alcohol are as follows:-
1. Hand sanitizer.
2. Thermometric liquid.
3. Fuel.
9.
Functions of organic fertilizer are as follows:-
(i) It provides essential nutrients to the plants.
(ii) It helps soil to retain water.
10.
Differences between axon and dendrites are as follows:-
11.
The differences between systemic blood circulation and pulmonary blood circulation are as follows:-
12.
Sex determination processes is represented by the given chart.
Zygote with chromosomes (44,xx) will develop into a female child while zygote with chromosomes (44,xy) will develop into a male child.
13.
The differences between drone bee and worker bee are as follows:-
14.
Meteor is generally finished before reaching the earth surface as they burn due to friction in the atmosphere.
15.
When the density of the object is more than water the object sinks in water.
16.
17.
As the red litmus paper remained unchanged the solution in vessel can either be acid or salt. For further testing a blue litmus paper is inserted in the solution if blue litmus turns into red it is acidic solution otherwise the solution is a salt solution.
18.
Uses of water glass are as follows:-
Uses of lead crystal glass are as follows:-
19.
20.
Following suggestion can help to reduce soil pollution:-
21.
Solution
Given
Focal length, f = 20 cm = 0.2 m
Object distance, u = 10 cm
Let, image distance be v
Magnification of the image, m = v/u = -20/10 = -2
Power of the lens, P = ⅟𝖿 = 1/0.2 = 5 Dioptre.
22.
(i) Carbondioxide (CO₂) gas is collected in the jar.
(ii) Carbondioxide (CO₂) gas is heavier than air so it can be collected by upward displacement of air hence the gas jar is kept erect.
(iii) 2KOH + CO₂ → K₂CO₃ + H₂O
23.
Law of purity of gametes can be observed in every generation. During gamete formation each pair of factor segregate into individual gamete and only on allele is transferred to the offspring from any pair of traits.
24.
The main chemical which destroys ozone layer is chlorofluorocarbons (CFCs).
The molecular formula of ozone layer is O₃.
The molecular formula of chlorofluorocarbon derived from an alkane CnH₂₍n₊₁₎ is
b. What is alternative source of energy?
That source of energy which can be used instead of non-renewable source of energy is called alternative source of energy.
c. In which two factors does the heat gain or loss by any object depend upon?
Two factors on which the heat gain or loss by any object depend upon are:-
- Mass of the object
- Specific heat capacity of the object
d. Define converging lens.
Converging lens is defined as the lense which converges a parallel beam of light coming from infinity fallen upon its surface to a point.
e. What is transformer?
Transformer is a device which converts a high voltage into low voltage or vice-versa.
f. Write the types of given chemical equation.
i) C + O2→ CO2
ii) 2KClO3 → 2KCl + 3O2
i) C + O2→ CO2This is combination chemical equation.
ii) 2KClO3 → 2KCl + 3O2This is decomposition chemical equation.
g. Define neutral salt.
Neutral salt is defined as salt which pH value is 7.
h. Name any two ores of iron.
Haematite and Magnetite are two ores of iron.
i. Write general formula of alkene.
The general formula of alkene is C₂H₂n.
j. Write the name of two species of silkworm cultivated in Nepal.
ERI and SERI are two species of silkworm cultivated.
k. Write the name of vein in which pure blood flows.
Pure blood flows in pulmonary vein.
l. Write any two chromosomal disorders caused by sex chromosome.
Chromosomal disorders caused by sex chromosome are Turner's syndrome and Klinefelter's syndrome.
m. What is the part of plant called that is used for root in grafting?
The part of plant that is used for root in grafting is called stock.
n. Mention any two effects of water pollution.
Spread of Water-borne disease and adverse effect on aquatic life and agriculture are two effects of water pollution.
o. In which eras do owl and flowering plants evolved?
Owl evolved in the cenozoic era and flowering plants evolved in the mesozoic era.
(Group 'B') 13x2=26.
2.
Kathmandu lies at high altitude than Biratnagar from sea level. Where does an object has more weight between two places? Give reason.
The object has more weight in Biratnagar. This is because acceleration due to gravity in Biratnagar is higher than Kathmandu.
3.
In the context Nepal, hydro power should be given more priority rather than fossil fuel. Why? Justify with two reasons.
Two reasons for which hydro power should be given more priority rather than fossil fuel are:-
Economic:- Hydropower is Nepal's own potential where it has to export fossil fuels from other nations.
Ecology:- Fossil fuel emits carbon and degrades surrounding while hydropower has no such adverse effect.
4.
What happens if an egg is kept in two beakers containing pure water and saturated salt solution? Why?
The egg kept in beaker containing pure water sinks while the egg kept in beaker containing saturated salt solution floats. This is so because pure water has lower density the egg while saturated salt solution has higher density than the egg.
5.
Mention any two reasons of using nichrome wire in electric heater.
Reasons for using nichrome wire in electric heater are:-
(i) Nichrome is resistant to air corrosion at high temperature.
(ii) Nichrome has melting point of 1400 ºC.
6.
Write any two characteristics of modern periodic table.
Two characteristics of modern periodic table are:-
- Elements are arranged on the basis of increasing atomic number.
- All the elements in a group have same valency.
Write the balanced chemical reaction between Aluminium metal and dilute hydrochloric acid. Mention the type of reaction with reason.
Aluminium reacts with dilute hydrochloric acid and form Aluminium chloride(AlCl₃) and hydrogen.
2Al + 6HCl → 2AlCl₃ + 3H₂↑
The reaction is single displacement reaction. Aluminium (Al) displaces hydrogen atom from HCl and combines with Cl to form AlCl₃.
8.
Write a structural formula of glycerol and write any one use of ethyl alcohol.
Glycerol is a trihydric alcohol. It is formed by replacement of three H atoms from propane by three hydroxyl(OH) functional group.
Uses of ethyl alcohol are as follows:-
1. Hand sanitizer.
2. Thermometric liquid.
3. Fuel.
9.
Write any two functions of organic fertilizer.
Functions of organic fertilizer are as follows:-
(i) It provides essential nutrients to the plants.
(ii) It helps soil to retain water.
10.
Write two differences between axon and dendrites.
Differences between axon and dendrites are as follows:-
11.
Write two differences between systemic and pulmonary blood circulation.
The differences between systemic blood circulation and pulmonary blood circulation are as follows:-
12.
Which process is represented by given chart?According to that process write down differences between (44, xx) and (44, xy) .
Sex determination processes is represented by the given chart.
Zygote with chromosomes (44,xx) will develop into a female child while zygote with chromosomes (44,xy) will develop into a male child.
13.
Write any two differences between drone bee and worker bee.
The differences between drone bee and worker bee are as follows:-
 |
| Drone bee Vs worker bee |
14.
Why is meteor generally finished before reaching the earth surface?
Meteor is generally finished before reaching the earth surface as they burn due to friction in the atmosphere.
Group "C" 6x3=18
15.
What is the condition for an object to sink in water?The cross-sectional area of piston A₁ and A₂ is 50 cm² and 0.2 m² respectively. How much load can be lifted in piston A₂ if 250N force is applied on piston A₁.
When the density of the object is more than water the object sinks in water.
16.
Prove that heat loss or gain by an object is equal to the product of mass of object, specific heat capacity and change in temperature.
Let heat gained or lost by body be Q
Mass of the body be mInitial temperature be T₁
Final temperature of body after cooling or heating be T₂
So, change in temperature, dt = T₂ - T₁
From observation it is found that heat gained or lost by body is directly proportional to its mass m.
i.e. Q ∝ m ……(i)
It is also found that heat gained or lost by body is directly proportional to change in temperature
i.e. Q ∝ dt ……(ii)
From ….(i) and ….(ii)
Q ∝ Mdt
From ….(i) and ….(ii)
Q ∝ Mdt
Q = smdt ……….(iii)
Q = msdt
Where, “s” is a constant of proportionality also called the specific heat capacity of the body.
Equation (iii) proves that heat gained or lost by an object is equal to the product of mass of object, specific heat capacity and change in temperature.
Q = msdt
Where, “s” is a constant of proportionality also called the specific heat capacity of the body.
Equation (iii) proves that heat gained or lost by an object is equal to the product of mass of object, specific heat capacity and change in temperature.
17.
In the given figure, red litmus paper is inserted in solution and colour remains unchanged then what may be contained in vessel among acid, base and salt solution. How can it be further tested to confirm it?
As the red litmus paper remained unchanged the solution in vessel can either be acid or salt. For further testing a blue litmus paper is inserted in the solution if blue litmus turns into red it is acidic solution otherwise the solution is a salt solution.
18.
Why is glass called fourth state of matter? Write any two uses of water glass and lead crystal glass.
Glass has solid-like property i.e. it has fixed shape and size but over long time objects made from glass experience its base thickning and upper part thinning. This is due to flow of glass molecules downward under the influence of gravity. This molecule flow property exhibits a liquid nature althoug extremely slow. That is why, glass is called fourth state of matter.
Uses of water glass are as follows:-
(i) Water glass is used to remove ink from paper while processing used paper.
(ii) Water glass is used as binder in detergent and soap
(iii) Water glass is used as binder in masonry products like concrete and plaster.
(iv) Water glass is used as an adhesive.
Uses of lead crystal glass are as follows:-
(i) Lead crystal glass is used for making lens and prism.
(ii) Lead crystal glass is used for making sparkling glass gems.
19.
Draw neat and clean diagram of reproductive part of plant and label its four major parts.
20.
What will you suggest to your neighbours so that it can help to reduce soil pollution? Write any six suggestions.
Following suggestion can help to reduce soil pollution:-
(i) Recycle waste product.
(ii) Use biodegradable product as much as possible.
(iii) Proper litter management.
(iv) Reduce the use of toxic product.
(v) Dumping of waste should be kept far from the residential area, farming area and water resource area.
(vi) Plantation at bare land.
Group 'D'
4x4=16
21.
Draw a ray diagram of an image formed when an object is placed at a distance of 10 cm from a convex lens having focal length 20 cm. Write any two nature of image. Calculate the power of lens.
Solution
Given
Focal length, f = 20 cm = 0.2 m
Object distance, u = 10 cm
Let, image distance be v
From lens formula
⅟𝖿 = ⅟𝗎 + ⅟𝗏
⅟₂₀ = ⅟₁₀ + ⅟𝗏
0.05 cm⁻¹ = 0.1 cm⁻¹ + ⅟𝗏
⅟𝗏 = 0.05 cm⁻¹ - 0.1 cm⁻¹
⅟𝗏 = - 0.05 cm⁻¹
v = - 20 cm
Here "-" sign indicates that image is in the same side of the object and at 20 cm distance from the optical center.
Ray diagram is drawn below:-
Magnification of the image, m = v/u = -20/10 = -2
Nature of the image:-
(I) Virtual
(II) Erect
(III) Twice magnified from the object size.
22.
Study the given diagram and answer the following questions.
i) Which gas is collected in gas jar?
ii) Why is the gas jar kept erect?
iii) What happen when gas is reacted with potassium hydroxide? Write the balanced chemical equation.
(i) Carbondioxide (CO₂) gas is collected in the jar.
(ii) Carbondioxide (CO₂) gas is heavier than air so it can be collected by upward displacement of air hence the gas jar is kept erect.
(iii) 2KOH + CO₂ → K₂CO₃ + H₂O
23.
Draw a chart to show the first generation and second generation resulted due to the fusion of gamets of long-winged housefly (HH) and short-winged housefly (hh). Which generation shows the law of purity of gamets? Justify it.
Law of purity of gametes can be observed in every generation. During gamete formation each pair of factor segregate into individual gamete and only on allele is transferred to the offspring from any pair of traits.
24.
Write the name of main chemical which destroys ozone layer. How is ozone layer depleted by that chemical? Describe with chemical equation.
The main chemical which destroys ozone layer is chlorofluorocarbons (CFCs).
The molecular formula of ozone layer is O₃.
The molecular formula of chlorofluorocarbon derived from an alkane CnH₂₍n₊₁₎ is
CnCl₍₂n₊₂-w₎Fw
For n=1 and w=2
The molecular formula of chlorofluorocarbon is
CCl₂F₂
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