Science
1. a. Which one of the following
represents analogue signal?
i.
Computer ii. Infrared thermometer
iii.
Smart watches iv. Medium wave radio
b. In a science laboratory, two
organisms are noticed. Both organisms are long
and cylindrical. Organism "A"
has cylindrical segmented body and organism
"B" has no segmented body. Then,
which of the following is correct?
i. Organism A is hermaphrodite
where as organism B is unisexual.
ii. Organism A is unisexual whereas
organism B is hermaphrodite.
iii. Organism A is diploblastic
whereas organism B is triploblastic.
iv. Organism A is triploblastic
whereas organism A is diploblastic.
c. Which of the following is the
phenotype ratio of monohybrid cross in
Mendel's experiment?
i.
1:2 ii. 3:1 iii. 1:2:1 iv. 9:1
d. An old man feels thirsty and urinates
frequently. Identify his disease:
i. high blood pressure ii.
Diabetes
iii. Heart attack iv. Low blood pressure
e. Which of the given equipment is
based on Archimedes’ principle?
i. Submarine
ii. Hydraulic
brake
iii. Water pump iv.
Thermometer
f. The magnetic flux inside the
solenoid is …………
i. smaller than outside ii. Equal to outside
iii. Greater than outside
iv. Some times smaller and greater than
outside.
g. Which of the following is not true
about Big Bang Theory
i. A singular huge explosion
ii. Universe expanded and
temperature came down
iii. Hydrogen and Helium formed
along with this expansion
iv. The gases condensed under
gravitation and formed the galaxies of the present
h. Glass containers are generally not recommended for collecting rainwater
samples. Why?
i. Glass containers are expensive
ii.
Glass containers are not easy to maintain
iii. Glass containers affect the pH of the rain
water
iv.
All of the mentioned
i. Which of the following is the
IUPAC name of glycerol?
i. methanol
ii. Ethylene iii. Ethanol iv. Propane 1,2,3 triol
j. Which of the following
pesticides degradation methods is harmless for the environment?
i. Microorganisms ii. Chemical methods
iii. Physical methods iv. Invertebrates
Answer:
2. a.
What do you mean by digital communication?
b.
c. What type of cell division is shown in the diagram? Where is such cell likely to be found?
d.
Name
any two valves present in human heart.
e.
On
what condition does a body become weightless inside of the earth’s
gravitational field?
f.
What
is the relation between specific heat capacity and rate of increase or decrease
in its temperature?
g.
Write
the formula equation for the chemical reaction between anyone of the very
reactive metal and very reactive non-metal.
h. Element of which group belongs to ‘p’ block in the periodic table?
i. What is calcination?
Answer:
3. Write any two differences
between bird and bat.
Answer:
4. If ‘A’ and ‘B’ are fertilized and unfertilized eggs respectively. Which type of honey bee is developed from ‘B’? Also, write one function of such bee.
Answer:
5. Describe the process of In Vitro
fertilization (IVF) in brief.
Answer:
6. A small portion of blood testing is shown in the figure. Identify the blood groups with logical reasons.
Answer:
7. Write down one use of each of following:
a) Titepati b) Cordyceps sinensis
Answer:
8. A patient claims that he has headaches, heart palpitations or
nosebleeds, blurry or double vision, shortness of breath, Nausea
and/or vomiting. What do you think about the case? What do you suggest?
Answer:
9. Prove the equation that acceleration due to gravity is inversely proportional to
the square of radius.
Answer:
10. Which type of defect of vision is given in the diagram of eye? Write one cause of it.
Answer:
11. A biology experiment requires the
preparation of a water bath at 37.00C
(body temperature). The temperature of the cold tap water is 22.00C, and the
temperature of the hot tap water is 55.00C. If a student starts with 90.0 g cold
water, what mass of hot water must be added to reach 37.00C?
Answer:
12. State Magnetic flux and magnetic flux density.
Answer:
13. What are the conditions for a universe to be closed, open or flat?
Answer:
14. A part of a periodic table is given study and answers the following questions.
|
Li |
Be |
B |
C |
N |
O |
F |
Ne |
|
Na |
Mg |
Al |
Si |
P |
S |
Cl |
Ar |
i. Which one is more active between Li and Na and why?
ii. Write down the chemical compound which is formed by combining Na
and Cl. Also mention the type of chemical bond formed.
Answer:
15. Structural formulae of some compounds are given below.
a) Which one of them is unsaturated hydrocarbon?
b) Write any one use of ‘c’.
Answer:
16. Write the full form of DDT, BHC, BHT and BHA .
Answer:
17. Study the parts editorial of CNN business website published in 14 November,2023 and answer the given questions.
a. How have social media declined the online reputation of people? Write any two. 2
b. What sort of contents are enhanced to publish in social media? Write any one mentioned above. 1
c. What should be the role of netizen to build the digital well being? Write any one role. 1
Answer:
18. Study the given table and answer the following questions:
|
Blood
cell |
Count
(in cubic mm) |
|
A |
4.5
milion-5.5 million |
|
B |
4k-11k |
|
C |
2
lacs-4 lacs |
a. Identify blood cells A and B.
b. Write major function of B and C.
c. Differentiate between A and C.
d. Name the disease that occur due to over production of B and deficiency
of A.
Answer:
19. When the white ray of light enters to the
prism, only the visible uppermost and
lowermost rays of light are shown in the
diagram
a. Name the rays A and B.
b. Which ray has more speed (A or B) in the
glass medium?
c. Which phenomenon is shown in the given diagram?
d. Ray B bends more than the ray A. What is the reason behind it?
Answer:
20. Alternating current generated in hydropower stations is transferred to
sub-power stations at a very high voltage. Sub-power stations send electricity
at 230 voltages for domestic use. However, mobile devices, torch lights,
laptops and many other devices run at lower voltages. Now, answer these
questions.
a) Which device helps to alter the voltage of AC? 1
b) Would AC be useful for us without device? Why? 2
c) How does this device help us to consume AC for domestic proposes? (1)
Answer:
21. The different weight of a piece
of a stone on weighing in three different
media; air, water and salt solution are
given in the table below. Answer the
following questions.
|
Medium |
Weight |
|
A |
15 N |
|
B |
20 N |
|
C |
17 N |
a) Which should be air, water and salt
solution out of these A, B and C? 1
b) If the weight of 1kg mass of stone in air
is 10N, find out the mass of the
piece of stone. 1
c) Find out the mass of
displaced water. 2
Answer:
22. Observe the following
laboratory setup for the preparation of a gas and
answer the questions.
a. Write the chemical reaction involved in this process.
b. Write any one test for the confirmation of production of this gas.
c. Is the gas prepared lighter or heaver than air?
d. Write any one application of the gas.
Answer:
23. How is our environment being polluted due to cement, soap, detergent and
insecticides? Write any two. Also, suggest any two measures to reduce
chemical pollution from above given materials.
Answer:
a) A student is confused on the independent
variable when her teacher taught
i)
Mass of the planet ii)
Radius of the plane
iii)
Mass of falling body iv) Acceleration due to gravity
b) Plant X is unicellular autotroph and plant
Y contains reticulate venation in its leaves with tap root system. Which of the
following are ‘X’ and ‘Y’?
i)
Algae and Pine ii) Moss and Sugarcane
iii)
Fern and Cycas iv)
Chlamydomonas and Mango
c) RNA
consists of …….
i)
Double helix structure with uracil in nitrogen base
iii)
Double helix structure with thymine in nitrogen base
ii)
Single helix structure with uracil in nitrogen base
iv)
Single helix structure with thymine in nitrogen base
d) Which
of the following is not true about ‘Gurjo’ and ‘Ghod tapre’?
i)
Gurjo contains anti-stress formula which can cure stress, anxiety.
ii)
Excessive consumption of Gurjo reduces sugar level in blood.
iii)
Gurjo is a climbing shrub useful to boost immunity.
iv)
Ghod tapre is a perennial herb capable of boosting memory power.
e) If the weight of a body at the surface of
earth is 400N, what will be its weight at 6.4
i)
0 ii) 100N iii) 200N iv) 400N
f)
Study the following statements related to anomalous expansion of water.
Which of them is not correct?
i)
Water has maximum density and minimum volume at 4oC.
ii)
Water contracts on both heating and cooling from 4oC.
iii)
Water expands on both heating and cooling from 4oC.
iv)
Fishes are alive under a pond with frozen surface due to anomalous expansion of water.
g) Study
the following statement and the arguments:
Statement:
Electricity can be generated due to the relative motion of conductor coil and
magnetic flux.
Argument
1: The induced emf is directly proportional to the rate of change of magnetic
flux.
Argument
2: The emf continues to induce even the magnetic flux stops changing.
i)
Statement and argument 2 are correct but argument 1 is incorrect
ii) Statement and argument 1 are incorrect
but argument 2 is correct
iii. Statement and arguments 1 are correct
but argument 2 is incorrect
iv. Statement is correct but both the
arguments are incorrect
h) The
concept of big crunch is related to:
i)
Hubble’s theory ii) open universe
iii)
flat universe iv) closed universe
i) f-block
elements are kept separately in modern periodic table:
i)
because they are late discovered elements
ii)
to avoid unnecessary expansion of the periodic table.
iii)
because they are not the metals, non-metals or metalloids.
iv)
because they have high energy
j) Which
of the following statement is correct?
i)
First class preservatives are obtained from natural sources and can be used in
necessary amounts in food.
ii)
Second class preservative are obtained from natural sources and can be used in
limited amounts in food.
iii)
Calcium carbide is the traditional food ripening agent.
iv)
Excessive use of chemical food ripening agents is good for our health.
Answer:
|
a |
b |
c |
d |
|
e |
f |
g |
h |
i |
j |
|
Ii |
iv |
ii |
i |
|
ii |
ii |
iii |
iv |
ii |
i |
Give very short answer to the
following questions.
a) Differentiate
between analogue and digital signal transmission.
b) Why are bats kept under class Mammalia?
c) How does meiosis cell division help to
maintain the constant number of chromosomes between generations?
d) Water freezes from the top and ghee
freezes from the bottom, why?
e) Define mirage.
Answer:
Answer Key and Marking Scheme Group-B
a. Analog transmission uses a continuous signal, while digital transmission uses a series of discrete pulses. (Any correct difference 1 mark)
b. Bats are classified as mammals because they give birth to live young, provide milk to their young, have fur ( mark)
c. Meiosis is a type of cell division that produces gametes, such as sperm and egg cells, with half the number of chromosomes as the parent cell. This ensures that when two gametes fuse during fertilization, the resulting zygote will have the same number of chromosomes as the parent cells (1 mark)
d. This is because water and ghee have different density behaviors when they cool down. Density is a measure of how tightly packed the molecules of a substance are. Most substances become denser as they lose heat, but water is an exception. Water reaches its maximum density at 4°C (39.2°F), and then becomes less dense as it cools further. This means that ice, which is solid water, is less dense than liquid water and floats on the surface12. Ghee, on the other hand, becomes denser as it cools down, like most substances. This means that solid ghee, which is ghee butter, is more dense than liquid ghee and sinks to the bottom3. Therefore, water freezes from the top and ghee freezes from the bottom. (1 mark)
e. A mirage is an optical phenomenon that occurs when light rays bend due to changes in air density, creating an image of something that is not really there. For example, a mirage can make it look like there is water in a desert or on a hot road. (1 mark)
3. The unit of force, Newton, is not a
fundamental unit but the unit of mass, Kg, is fundamental unit, why?
Answer:
3. Newton is the unit of force.
F=mass x acceleration
= kg x m/s2
Fundamental units: Kg, m and s. (1-mark)
4. List out any two characteristics of class
gymnosperm.
Answer:
They do not produce
flowers.
5. Explain the importance of parthenogenesis
in the context of honeybee in any two points.
Answer:
3. helps in determining the sex of an individual, with drone bees produced by parthenogenesis. Female worker honey bees are formed from only fertilized eggs (2 mark)
6. Write differences between invitro
fertilization and artificial insemination.
Answer:
3. Artificial insemination is the deliberate introduction of sperms into a female cervix or uterine cavity, achieving in vivo fertilization, whereas in vitro fertilization is the process of fusion of egg and sperm outside the female body. Furthermore, artificial insemination involves injecting sperms into the uterus, decreasing the egg’s time of travel, while in vitro fertilization involves egg stimulation, retrieval, fertilization, and transfer. (2 marks)
7. What happens when the number of platelets
is abruptly increased or decreased in our blood?
Answer:
3. If the platelets in your blood keep increasing, it could lead to unnecessary clotting in your blood vessels, which could cause heart attack and stroke. (1 mark)
8. Following snippet is taken from Nepal’s Tigers: A Conservation Success Story | U.S. Fish & Wildlife Service (fws.gov)
In the early 1900s, there were an estimated
100,000 tigers on the Indian subcontinent, but by the early 2000s, tiger
numbers and their habitats were devastated. Nearly 95% of their habitats were
destroyed, and tiger numbers were decimated by poaching. Today, tigers are also
impacted by declining populations of prey due to a number of factors and
possibly exacerbated by climate change. Rural communities adjacent to protected
areas that harbor tigers have always faced a degree of conflict with these
predators. This conflict has steadily increased with growing human populations.
The poaching of tigers continues to feed the illegal
trade in tiger pelts, bones, claws, teeth, and other body parts. Poaching and
wildlife trafficking of tigers has been and continues to be a major threat to
wild tigers across their entire range, including in Nepal.
i) Read the above paragraph and mention any one cause other
than mentioned above.
ii) How can you contribute for the conservation of the species?
Answer:
3. i. Loss of habitat - (or any one 1 mark)
ii. Government legislation: Laws and regulations can protect endangered species from threats like poaching, habitat loss, and invasive species. (or any one 1 mark)
9. The up thrust offered by three different
media ‘A’, ‘B’ and ‘C’ to a piece of stone is found to be 0 N, 20N and 15N in
respectively.
i) If the media are air, water and salt solution. Which one of these is salt solution and why? (1)
ii) Calculate the weight of water displaced when the stone is dipped in water. (1)
Answer:
3. i. A is salt solution (1 mark)
ii. After calculation if answer is 3 N. (1 mark)
10. If
the final temperature of water is
Answer:
3. Correct given denoted (0.5 mark)
Correct formula heat gained= heat lost (0.5 mark)
Correct Calculation (0.5 mark)
Correct answer 150C (0.5 mark)
11. Draw the ray diagram when an object is
kept at 20cm in front of a convex lens with focal length 40 cm. Also, mention
the nature of image formed.
Answer:
3. Correct ray diagram with correct consideration of the length and correct nature of image (2 marks)
|
Elements |
Electronic configuration |
|
A |
3s23p4 |
|
B |
3s23p5 |
|
C |
4s2 |
12. Study the table alongside and answer the
following questions:
i) In
which period of modern periodic table, element C belong to? Why?
ii)
Which one is more reactive between A and B? Why?
Answer:
3. i. Calcium lies in the 4th period because it has 20 electrons and its electron configuration is 1s22s22p63s23p64s2. The 4th period corresponds to the filling of the 4th shell, which can hold up to 18 electrons. Calcium has two electrons in its 4th shell, so it belongs to the 4th period. (1 mark)
ii. Oxygen is more reactive, oxygen has to gain 2 electron and nitrogen has to gain 3 electrons to be stable and it is easier to oxygen to gain 2 electrons than nitrogen. (1 mark)
13. Have you ever noticed that why our hairs get rough
after applying shampoo and again turn shiny after we add conditioner? Why? Also
mention the type of reaction occurred.
Answer:
3. This is because our shampoo is basic in nature and conditioner is acidic in nature and that’s why it neutralizes the effect of the shampoo. (1 mark)
Type of reaction (1 mark)
14. All ores are minerals but all minerals
are not ores, why?
Answer:
3. All ores are minerals, while all minerals are not ores because the metal can't be extracted economically from all the minerals12. Metal may occur in a number of minerals but every mineral is not suitable for the extraction of the metal (2 marks)
15. The hydrocarbons represented by general
formula
Answer:
3. i. Alkanes are called paraffins because they have a little affinity towards a general reagent. In other words, alkanes are inert substances. They undergo reactions under drastic conditions. (1 mark)
ii. Correct use of ethane (1 mark)
16. Excessive use of calcium carbide as
artificial food ripening agent should be stopped. Justify your answer in two
points.
Answer:
3. i. it can cause severe irritation and burns with likely permanent damage to eyes and skin. (1 mark)
ii. It is prone to cause explosions and fire hazards when exposed. (1 mark)
Group
D (7x4=28)
Give long answer to the following questions.
17. Study the given snippet from and answer
the following questions:
“There
is almost no area in which digital technology has not impacted me and my
family’s life. I work more from home and have more flexibility and a global
client base because of digital technology. I monitor my health and keep my
physician informed using data technology. My wife has gone back to a graduate
school program and is much more connected to school because of technology. My
entertainment and reading options have exploded exponentially because of new
technologies. Use of home speakers, Internet of Things, AI [artificial
intelligence] and other emerging technologies is just impacting my life and
likely will become more central.”
i)
Mention the importance of digital technology in the authors life. (1)
ii)
How do the principles of digital well-being are useful to the author? (2)
iii)
How can the author manage his online reputation? (1)
Answer:
3. i. monitoring health, entertainment, reading (1 mark)
ii. Digital well-being comes in with a roadmap, a compass and actionable practices for how we can achieve more balance in our daily lives. This helps promote well-being and productivity, foster meaningful relationships and support physical and cognitive health, on an individual, organizational and societal level (2 mark)
iii. Any one method of managing online reputation. (1 mark)
18. The cross is made between pea plants with
red flower and white flower. All the plants of first filial generation
contained red flower only but there are some plants with white flower also in
second filial generation.
i)
Which of the colour of flower is the dominant character, why? (1)
ii)
What is the reason behind the appearance of white flower in pea plants of
second generation? (1)
iii)
Represent above information in chart with the genotype and phenotype ratios up
to second generation. (2)
Answer:
3. i. Pure red flower, RR (1 mark)
ii. because due to the law of segregation as during the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each gene. (1 mark)
iii. Correct chart and result (2 marks)
19. List out the risk factor and preventive measures
of heart attack.
Answer:
20. The web page https://en.wikipedia.org/wiki/International_
Space Station
The
International Space Station (ISS) is the largest space station to have ever
been built. The station resides in low Earth orbit and has a primary purpose of performing microgravity and
space environment experiments. As implied by its name, the International Space
Station is a collaboration of five national space agencies and other
contractors. These agencies are: NASA (United States), Roscosmos (Russia), JAXA
(Japan), ESA (Europe), and CSA (Canada). Functionally, the station is divided
into two sections: the Russian Orbital Segment assembled by Roscosmos and the
US Orbital Segment assembled by NASA, JAXA, ESA and CSA. The ISS maintains an
orbit with an average altitude of 400 kilometers and circles the Earth in
roughly 93 minutes, completing 15.5 orbits per day (meaning that it passes over
a fixed point on earth approximately once every 90 minutes).
i)
What is the weight of person inside ISS in ideal condition? (1)
ii)
If a mass of 50kg was placed instead of ISS, what will be its weight at the same
height? (2)
iii)
State the law which explains the force between ISS and earth. (1)
Answer:
20. a. Transformer (1 mark)
b. Use of AC would be limited because without transformer we cannot alter the voltage as required for the devices. (2 mark)
c. By changing the low AC to high and vice-versa, (1 mark)
Answer:
21. i. Causes (2 marks)
-Ciliary muscles fail to stretch the eye lens to its required focal length
- Elongation of eye ball
ii. Concave lens of suitable focal length should be used (1 mark)
iii. Reasons
§ They provide a wider field of view than glasses, as they move with your eye and do not block your peripheral vision.
§ They are more suitable for sports and physical activities, as they do not fog up, get wet, or fall off your face
Answer:
3. Power adaptors and rectifiers to efficiently decrease the voltage for electronic devices and Electronic SMPS (switched-mode power supply) to convert AC to DC power with high efficiency (1 mark)
ii. Correct calculation including formula (2 marks)
iii. To prevent from eddy current (1 mark)
Answer:
3. i. Ammonia (1 mark)
ii. Ammonia gas is collected in an inverted gas jar by the downward displacement of air. This is because ammonia is lighter than air and rises up, while air is heavier and sinks down. (1 mark)
iii. by using suitable litmus paper and pungent space. (1 mark)
ii. Correct use (1 mark)
Answer:
Answer:
Answer:
4. List out any two characteristics of class gymnosperm.
Answer:
5. Explain the importance of parthenogenesis in the context of honeybee in any two points.
Answer:
6. Write differences between invitro fertilization and artificial insemination.
Answer:
Answer:
Answer:
Answer:
10. If the final temperature of water is
Answer:
11. Draw the ray diagram when an object is kept at 20cm in front of a convex lens with focal length 40 cm. Also, mention the nature of image formed.
Answer:
Answer:
13. Have you ever noticed that why our hairs get rough after applying shampoo and again turn shiny after we add conditioner? Why? Also mention the type of reaction occurred.
Answer:
14. All ores are minerals but all minerals are not ores, why?
Answer:
Answer:
Answer:
Answer:
Answer:
19. List out the risk factor and preventive measures of heart attack.
Answer:
Answer:
Answer:
Answer:
Answer:
