Science

a. Which is the smallest unit of computer memory?
(i) Kilobyte
(ii) Megabyte
(iii) Bit
(iv) Gigabyte

b. Why is pine kept in sub-division gymnosperm?
(i) It has needle shaped leaves.
(ii) It has naked seeds.
(iii) It has chlorophyll.
(iv) It has cones instead of fruit.

c. Which of the following groups of organisms are closely related on the basis of evolution?
(i) Porifera, Annelida, Chordata
(ii) Porifera, Arthropoda, Chordata
(iii) Coelenterata, Arthropoda, Chordata
(iv) Platyhelminthes, Nemathelminthes, Annelida

d. What is the main cause of increasing the level of ocean?
(i) Deforestation
(ii) Heavy rainfall
(iii) Flood and landslide
(iv) Increase in the temperature of the earth

e. Calculate the mass that a person can lift on moon if he can lift a mass of 50 kg on the earth. The value of g on the surface of the Earth is 9.8 m/s2 and that of moon is 6 times less.
(i) 200.6 kg
(ii) 300.6 kg
(iii) 400.6 kg
(iv) 500.6 kg

f. If large piston A and small piston B of a hydraulic lift have their cross-sectional area, pressure and force/weight as A1 and A2, P1 and P2, and F1 and F2 respectively, then which of the following relations would be correct according to Pascal's law?
(i) P1 > P2
(ii) A1 < A2
(iii) F1 > F2
(iv) F1 < F2

g. Identify the characteristics of the image of the object XY kept in front of the lens as shown in the given figure.

(i) Virtual, erect and magnified
(ii) Real, erect and magnified
(iii) Virtual, inverted and diminished
(iv) Real, inverted and magnified

h. Which of the following is proved by Hubble's law?
(i) Universe is contracting.
(ii) Universe is expanding.
(iii) Universe remains same.
(iv) Galaxies appeared to be closer.

i. Which one is a double displacement reaction from the following?
(i) X + YZ → XY + Z
(ii) X + Y → XY
(iii) XYZ → X + Y + Z
(iv) XY + AB → XB + AY

j. A statement and two arguments are given below.
Statement: Detergent is called a soap-less soap.
Argument 1: It has cleaning properties like soap but its chemical nature is different.
Argument 2: It does not give lather with hard water as soap.
(i) Statement and argument 2 is correct but argument 1 is incorrect.
(ii) Statement and argument 2 is incorrect but argument 1 is correct.
(iii) Statement and argument 1 is correct but argument 2 is incorrect.
(iv) Statement and argument 1 is incorrect but argument 2 is correct.

a. Write an advantage of independent variable.

b. What is upthrust?

c. Write down one utility of optical fiber.

d. In summer season, the cemented roads seem to be filled with water but they are not actually. Which phenomenon of light is behind this?

e. What happens when carbon dioxide gas is passed through lime water for a short time?

f. What is meant by redshift?

g. Write the name of the main ore of silver.

h. Why are group VII elements of the periodic table called halogens?

i. Write the structural formula of glycol.

Use fundamental units to show that equation P = IV is homogeneous, where I is electric current, V is voltage and P is power.

Write any two characteristics of the plant kingdom.

Write any two roles of the honey bee in the ecosystem.

Mitosis cell division is called equational division. Why?

India has donated Murrah Buffalo to Nepal. Mention any two benefits gained by farmers on breeding buffalo with Murrah buffalo instead of local species of buffaloes.

Write any two differences between haemophilia and leukemia.

Number of red pandas is decreasing in Nepal. What measures can be done to protect the panda? Write any two measures.

Write any two factors on which gravity on the surface of a heavenly body depends.

Prove that if the earth attracts two bodies placed at the same distance from the centre of the earth with the same force, then their masses are equal.

A lamp is lit in a running bicycle by the help of a dynamo but it goes off when the bicycle is stopped. Give reason.

In domestic household wiring, voltage of 220V is supplied. A battery of a mobile works with 3.7V. Draw the net diagram of the transformer used in a mobile charger.

Write a balanced chemical equation between the reactions of a metal of group IIA with a non-metal of group VIIA.

Write the name of the member of alkyne which contains an equal number of hydrogen and carbon. Write one use of it.

"It is dangerous to use chemical pesticides for human health." Justify this statement by using your two arguments.

Write any two positive and negative impacts of digital technology in our daily life.

Study the figure and answer the following questions.(i) [1] What is the special property of water shown in the figure called?
(ii) [2] Write the change that takes place in the volume of water on heating from 0°C to 10°C.
(iii) [1] Write one use of this special property of water.
(Graph: Density of water (g/cm³) vs Temperature (°C), showing points A, B, C, D with peak density near 4°C)

(a) [1+1] What is an artery? Name the largest artery of the human body.
(b) [2] Write two causes of high blood pressure.

In the figure, A, B and C are three metal objects of equal mass and volume. They are heated to the same temperature and then placed in a vessel containing solid wax. The specific heat capacities of A, B and C are 380 J/kg°C, 470 J/kg°C and 910 J/kg°C respectively. Based on this information, answer the following questions:(a) Which metal has the highest amount of heat energy?
(b) Which metal goes the deepest into the wax vessel?
(c) Which metal cools down the fastest?
(d) Which metal has the highest amount of heat loss?

Write two differences between concave and convex lens.
The power of the lens used in the spectacles worn by a student is −6D. Calculate the focal length of the lens. Also, mention the type of lens.

Study the electronic configuration of two elements X and Y and answer the given questions.
X → 1s², 2s²2p⁶, 3s²3p⁶, 4s²
Y → 1s², 2s²2p⁶, 3s²3p⁵
(a) [1] Which one is metal?
(b) [1] Write the period of element Y.
(c) [2] Write the balanced chemical equation of the compound formed by combination of X and Y.

Study the given diagram and answer the following questions.(a) Which gas is being collected in the gas jar?
(b) What are A & B in the figure?
(c) What coloured litmus paper is used to identify such gas?