Group (Physics)
1. (a) What is transverse wave? Write one effect of reverberation. [2]
Answer
If the particles medium vibrate perpendicular to the direction of the motion of the wave, such a wave is called transverse wave.
Due to effect of reverberation, original sound gets reflected and reflected sound mixes with original sound and prolongation of sound occurs.
Due to effect of reverberation, original sound gets reflected and reflected sound mixes with original sound and prolongation of sound occurs.
(b) What is magnetic induction? Magnets are not hammered or rubbed, why? [3]
Answer
The process in which a piece of magnetic material acquires the magnetic properties temporarily due to the presence of magnet near or in contact with it is called the magnetic induction.
Magnets are not hammered or rubbed because
i. If a magnet is rubbed on hard substances it’s loses its magnetism.
ii. On hammering, the vibration caused by the impact on the magnetic molecules within the magnet, forcing them out of order and destroying the long-range order of the unit magnet. As a result, the magnet gets demagnetized.
Magnets are not hammered or rubbed because
i. If a magnet is rubbed on hard substances it’s loses its magnetism.
ii. On hammering, the vibration caused by the impact on the magnetic molecules within the magnet, forcing them out of order and destroying the long-range order of the unit magnet. As a result, the magnet gets demagnetized.
2. (a) What are the differences between MKS system and FPS system? [2]
Answer
The differences between MKS system and FPS system are;
| MKS system | FPS system | |
|---|---|---|
| Definition | The system of measurement in which length is measured in 'metre', mass in 'kilogram' and time in 'second' is called MKS system. | The system of measurement in which length is measured in 'foot', mass in 'pound' and time in 'second' is called FPS system. |
| Full-form | In MKS system, MKS is the abbreviated form of units; Metre, Kilogram and Second. | In FPS system, FPS is the abbreviated form of units; Foot, Pound and Second. |
(b) Write two differences between heat and temperature. [2]
Answer
Differences between heat and temperature are as followings:
| Heat | Temperature |
| It is a form of energy that gives sensation of warmth. | It is the degree of hotness and coldness of a body. |
| It is a cause of change of temperature. | It is an effect of heat. |
3. (a) Sound can travel without medium. Write on the basis of following points:
i. Materials required
ii. Procedure
iii.Conclusion
[3]
i. Materials required
ii. Procedure
iii.Conclusion
[3]
Answer
Sound cannot travel without medium.
Materials required
• Electric bell
• Glass bell jar
• Vacuum pump
An experiment showing sound cannot travel without medium
Procedure
An electric bell is suspended inside a glass bell jar as shown in figure below. When the switch is pressed on, the hammer hits the gong and sound is heard. Then, the air present inside the bell jar is allowed to escape through the vacuum pump. Now, the sound becomes fainter and fainter and finally no sound can be heard though the hammer hits the gong continuously.
Observation
It is observed that the hammer hits the gong continuously but we hear no sound after the air is taken out from the bell jar.
Conclusion
From above experiment it can be concluded that sound does not travel through vacuum, it requires material medium to travel.
Materials required
• Electric bell
• Glass bell jar
• Vacuum pump
An experiment showing sound cannot travel without medium
Procedure
An electric bell is suspended inside a glass bell jar as shown in figure below. When the switch is pressed on, the hammer hits the gong and sound is heard. Then, the air present inside the bell jar is allowed to escape through the vacuum pump. Now, the sound becomes fainter and fainter and finally no sound can be heard though the hammer hits the gong continuously.
Observation
It is observed that the hammer hits the gong continuously but we hear no sound after the air is taken out from the bell jar.
Conclusion
From above experiment it can be concluded that sound does not travel through vacuum, it requires material medium to travel.
(b) What is output work? [2]
Answer
The efficiency of a simple machine is 80%, it means that only 80% of input work applied to the machine can do output work, remaining 20% input work is wasted due to friction.
4. (a) What is magnetic induction? [2]
Answer
The property of a magnet by virtue of which it is transferred to another body which is attracted by it for a while is called a magnetic induction. It is a temporary process because of which magnetic materials in contact with the magnet acquires temporary magnetic properties.
(b) Alcohol thermometer cannot be used to measure the boiling point of water, why? [2]
Answer
Alcohol thermometers are filled with alcohol. Water has boiling point 100ᵒC. The boiling point of alcohol is 78ᵒC, so alcohol thermometer cannot measure the temperature greater than 78ᵒC. Hence,alcohol thermometer cannot be used to measure the boiling point of water.
5. (a) The distance from Thapathali to Koteshwor is 4 kilometres. Convert this value in terms of metre. [3]
Answer
Here, we have to convert the kilometre value of length into metre.
For that, we need to remember the relationship between kilometre and metre.
We know the relationship between kilometre and metre is;
One kilometre is equal to 1000 metres.
Therefore,4 kilometres is equal to 4000 metres.
For that, we need to remember the relationship between kilometre and metre.
We know the relationship between kilometre and metre is;
One kilometre is equal to 1000 metres.
1 km = 1000 m
The distance from Thapathali to Koteshwor is equal to 4 kilometres.Distance = 4 km
As we need the value of 4 kilometres in terms of metres, let us multiply 4 by the unit value of kilometre in terms of metre.4 km = 4×1000 m
Multiplying 4 and 1000 together, we get 4000.Therefore,4 kilometres is equal to 4000 metres.
∴ 4 km = 4000 m
Hence, the distance from Thapathali to Koteshwor in terms of metre is equal to 4000 metres. (b) What are the differences between mass and weight? [2]
Answer
The differences between mass and weight are;
| Mass | Weight | |
|---|---|---|
| Definition | Mass is the quantity of matter which is contained in a body. | Weight is the force acting on the mass of a body due to gravity. |
| Measuring device | Mass is measured using 'beam balance'. | Weight is measuredusing 'springbalance'. |
| Uniformity | Mass does not vary from place to placei.e. the mass of a body is always constant in every place of the universe. | Weight varies from place to place i.e. the weight of a body measured in a place is different from the weight measured in another place of the universe. |
| Type of quantity | Mass is a scalar quantity. | Weight is a vector quantity. |
Group (Chemistry)
6. (a) What is semi-conductor? Write any two properties of aluminium. [2]
Answer
Those substances which are bad conductor of heat and electricity are termed as semiconductors.
Properties of aluminium are as followings:
• They possess metallic lustre when they are freshly cut.
• They are good conductor of heat and electricity.
Properties of aluminium are as followings:
• They possess metallic lustre when they are freshly cut.
• They are good conductor of heat and electricity.
(b) Write any one use of copper and aluminium. [2]
Answer
Uses of copper and aluminium-
• Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, window frames, beer kegs and aeroplane parts.
• Copper is used in electrical equipment such as wiring and motors.
• Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, window frames, beer kegs and aeroplane parts.
• Copper is used in electrical equipment such as wiring and motors.
7. (a) Show two differences between sodium carbonate and sodium bicarbonate. [2]
Answer
Differences between sodium carbonate and sodium bicarbonate are as followings:
| Sodium carbonate | Sodium bicarbonate |
| Sodium carbonate is commonly known as ash soda and washing soda. | Sodium bicarbonate is commonly known as baking soda. |
| Sodium carbonate is used in manufacturing glass and soap. | It is used in food industries. |
(b) Which acids are found in lemon and milk? Give any two properties of base. [3]
Answer
Citric acid is found in lemon and lactic acid is found in milk.
Properties of base are as followings:
i. Bases have bitter taste and they are soapy to touch.
ii. Bases have a pH value greater than 7.
Properties of base are as followings:
i. Bases have bitter taste and they are soapy to touch.
ii. Bases have a pH value greater than 7.
8. (a) Write any one difference between mixture and compound. Mention the charge of proton and electron. [2]
Answer
Difference between mixture and compound is as following:
Proton contains positive charge while electrons contain negative charge.
| Mixture | Compound |
| A mixture is a material made up of two or more different substances which are mixed but are not combined chemically. | A substance made from the chemical reaction of two or more atoms of elements in a fixed proportion by weight is called compound. |
Proton contains positive charge while electrons contain negative charge.
(b) Write about position of metals, metalloids and non-metals in periodic table. What is sulphur? [3]
Answer
In periodic table metals are placed in group IA(except hydrogen) and IIA, non-metals are placed in left side of periodic table (group IIIA, VA, VIA and VIIA) and metalloid are kept in group IVA of periodic table.
Group (Biology)
9. (a) Write one function each of RBC, WBC and platelets. [3]
Answer
RBC: The function of RBC is to transport oxygen and carbon dioxide in our body.
WBC: The function of WBC is to fight against germs that cause diseases.
Platelets: The function of platelets is to protect the body from loss of blood.
WBC: The function of WBC is to fight against germs that cause diseases.
Platelets: The function of platelets is to protect the body from loss of blood.
(b) Explain, how could you prove experimentally that, oxygen gas is released during photosynthesis by green plants. [3]
Answer
Material required:
Beaker, funnel, test tube, hydrilla plant.
Procedure:
Take some healthy, fresh branches of hydrilla plant in a funnel and invert in a beaker. Put water in the beaker till the end of the funnel is under water as shown in figure. Take a test tube full of water and close its mouth with a thumb. Then invert it over the stem of funnel and release the thumb. Such method is applied so as to keep the test tube free of air. Keep the set undisturbed in the sunlight for a while.
Observation:
After a short time some bubble of gas in the test tube is produced. The gas so evolved is collected at the top of test tube. Take it out and bring burning match stick near the tube. The test-tube will steak light.
Figure in copy
Fig: Oxygen is evolved during photosynthesis.
Result
The evolved gas is oxygen which helps in burning.
Conclusion
O2 is evolved during photosynthesis.
Beaker, funnel, test tube, hydrilla plant.
Procedure:
Take some healthy, fresh branches of hydrilla plant in a funnel and invert in a beaker. Put water in the beaker till the end of the funnel is under water as shown in figure. Take a test tube full of water and close its mouth with a thumb. Then invert it over the stem of funnel and release the thumb. Such method is applied so as to keep the test tube free of air. Keep the set undisturbed in the sunlight for a while.
Observation:
After a short time some bubble of gas in the test tube is produced. The gas so evolved is collected at the top of test tube. Take it out and bring burning match stick near the tube. The test-tube will steak light.
Figure in copy
Fig: Oxygen is evolved during photosynthesis.
Result
The evolved gas is oxygen which helps in burning.
Conclusion
O2 is evolved during photosynthesis.
10. (a) Where does the epithelial tissue lie? Write any two function of it. [3]
Answer
The epithelial tissue lies in Animal tissue.
The two function of epithelial tissue are:
i. To protect skin.
ii. Absorption of intestinal lining.
The two function of epithelial tissue are:
i. To protect skin.
ii. Absorption of intestinal lining.
(b) What is a system? Mention a name of any one system of human body? [2]
Answer
A group of different organs which conducts a particular life process is called system. The name of one system of human body is skeletal system.
11. (a) What is vegetative propagation? Write any two examples [2]
Answer
The process of reproduction by the vegetative parts such as root, stem and leaves are called vegetative propagation. Potato and ginger are the two example of vegetative propagation.
(b) What is asexual reproduction? Write the name of reproduction process that occurs in tapeworm. [3]
Answer
A type of reproduction that occurs without the fusion of male and female gametes is called asexual reproduction. Regeneration is the name of reproduction process that occurs in tapeworm.
Group (Astronomy and Geology)
12. (a) How many types of soil are there on the basis of colour, size and composition? Describe them in brief. [3]
Answer
There are three types of soil on the basis of colour, size and composition. They are:
i) Loam soil: Loam soil is the combination of sand, clay and humus in good proportion. It is fertile soil which is good for cultivation of crops.
ii) Clay soil: Clay soil is the soil which has small and tightly packed particles. Water does not flow freely through this soil.
iii) Sandy soil: Sandy soil is the soil which contains high proportion of sand particles. Water can easily pass through this soil.
i) Loam soil: Loam soil is the combination of sand, clay and humus in good proportion. It is fertile soil which is good for cultivation of crops.
ii) Clay soil: Clay soil is the soil which has small and tightly packed particles. Water does not flow freely through this soil.
iii) Sandy soil: Sandy soil is the soil which contains high proportion of sand particles. Water can easily pass through this soil.
(b) Why do erosion and deposition take place side by side? Write any four effects of erosion. [3]
Answer
Erosion and deposition take place side by side because on process of them is a must for or after another process.
Four effects of erosion are as follows:
i) Erosion causes landslide.
ii) Erosion forms plains, plateaus and Residual Mountain like landscapes.
iii) Erosion decreases the soil fertility.
iv) Erosion may cause water pollution.
Four effects of erosion are as follows:
i) Erosion causes landslide.
ii) Erosion forms plains, plateaus and Residual Mountain like landscapes.
iii) Erosion decreases the soil fertility.
iv) Erosion may cause water pollution.
Group (Environment Science)
13. (a) What is acid rain? Write some impacts of acid rain. [3]
Answer
Rain with high levels of nitric and sulphuric acids is called acid rain. Some of the impacts of the acid rain are as follows:
i. Acid rain damages forests and kills the trees.
ii. Soil loses fertility so the crops are destroyed or not able to grow.
iii. Houses, statues, monuments made out of limestone, sandstone and marbles are destroyed because acid rain can melt such items.
iv. Fishes of lake, streams and rivers are affected because acid rain causes lack of oxygen.
i. Acid rain damages forests and kills the trees.
ii. Soil loses fertility so the crops are destroyed or not able to grow.
iii. Houses, statues, monuments made out of limestone, sandstone and marbles are destroyed because acid rain can melt such items.
iv. Fishes of lake, streams and rivers are affected because acid rain causes lack of oxygen.
(b) How many types of forest are there in Nepal? Write them. [2]
Answer
There are mainly two types of forest in Nepal. They are:
a) Government Managed Forest:
i. Community Forest
ii. Leasehold Forest
iii. Protected Forest
iv. Religious Forest
b) Private Forest ( managed by individual households )
a) Government Managed Forest:
i. Community Forest
ii. Leasehold Forest
iii. Protected Forest
iv. Religious Forest
b) Private Forest ( managed by individual households )
14. (a) How can we conserve biodiversity? [2]
Answer
The things we can do to conserve biodiversity are as follows:
i. Do not do things that could cause fire in the forest or any other places.
ii. Follow the rules and regulations strictly.
iii. Go for wise use of natural resources.
iv. Report any mishap or wrong doings if seen or found, to the authority.
i. Do not do things that could cause fire in the forest or any other places.
ii. Follow the rules and regulations strictly.
iii. Go for wise use of natural resources.
iv. Report any mishap or wrong doings if seen or found, to the authority.
(b) Write some importance of medicinal plant. [3]
Answer
Some of the importance of the medicinal plants is as follows:
i. They are chief raw materials for the manufacture of present age drugs and medicines.
ii. They are comparatively safe, eco-friendly and locally available.
iii. As herbs are natural products, they are free from side effects.
iv. They have a great traditional value in our culture and religion.
i. They are chief raw materials for the manufacture of present age drugs and medicines.
ii. They are comparatively safe, eco-friendly and locally available.
iii. As herbs are natural products, they are free from side effects.
iv. They have a great traditional value in our culture and religion.
15. (a) Write some activities of ICIMOD. [3]
Answer
ICIMOD stands for International Centre for Integrated Mountain Development. Some of the activities of ICIMOD are as follows:
i. Provide training facilities to improve the skills and the technical knowledge of farmers.
ii. Conduct research for applied/practical conservation.
iii. Investigate the impact of climate change on biodiversity and livelihoods.
iv. Manage biodiversity as a resource of income for local communities as well as a heritage for society.
i. Provide training facilities to improve the skills and the technical knowledge of farmers.
ii. Conduct research for applied/practical conservation.
iii. Investigate the impact of climate change on biodiversity and livelihoods.
iv. Manage biodiversity as a resource of income for local communities as well as a heritage for society.
(b) Write short note on
i. Genetic diversity
ii. Proper use of resources
[2]
i. Genetic diversity
ii. Proper use of resources
[2]
Answer
i. Genetic diversity:
Genetic diversity is the variation in the hereditary unit that transfers parental characteristics to their offspring. It depends on the population of the organism.
ii. Proper use of resources :
The need to increase efficiency and productivity while preserving natural resources, especially water and soil, is great. In light of these realities, growers are under pressure to produce more, pollute less, fulfill consumer preferences, and make a living.
Genetic diversity is the variation in the hereditary unit that transfers parental characteristics to their offspring. It depends on the population of the organism.
ii. Proper use of resources :
The need to increase efficiency and productivity while preserving natural resources, especially water and soil, is great. In light of these realities, growers are under pressure to produce more, pollute less, fulfill consumer preferences, and make a living.