B.El.Ed. Natural Science PYQ

B.El.Ed. – I Year Annual examination 2024

C1.3

Core Natural Science

Time: 2 Hours Maximum Marks: 35

1. ldentify whether the given statement is true or false.

Give reason in support of your answer. (1x5)

(a) Water and minerals are transported from leaves

to the other parts of the plants through the xylem

tissues.

(b) An object with zero velocity can have non-zero

acceleration.

(c) Boiling can remove all types of hardness in water.

(d) Rust formed on iron objects is basic in nature.

(e) Concave mirrors always form a real and inverted

image.

2. (a) What happens to the blood when it passes through

the kidneys? (1)

(b) X is a chemical substance used in antacids and baking products. Dissolving X in water produces a gas with effervescence.

(i)) Identify X and write its common name.

(ii) Write the reaction of X with water.

(1+1)

(c) An equal amount of pale green solution of ferrous sulphate was taken in two separate test tubes marked I and II. Pieces of Silver and Aluminium wére dropped in test tubes I and II respectively. In which of the two test tubes, reaction will take place? Give reasons. Also, write a balanced chemical équation for the reaction. (2)

3. (a) Three blocks A, B and C of identical sizes are

suspended in water using strings, as shown in the

figure below. Blocks B and C have the same mass

while the mass of Block A is more. Rank the

blocks A, B and C in the increasing order of

buoyant force acting on them. Explain the reason

also. (2)

OR (only for VI candidates)


(a) A stone is immersed in two liquids A and B, one

after the other. The weight of stone in the air is

150 N. The weight of the stone in liquid A

and liquid B is 120N and 95N respectively. Which

liquid will exert a greater buoyant force? Give

reason. (2)


(b) Peter made ORS solution at home but later

discovered that he had accidentally added chalk

powder instead of salt. Is there any way he can

separate all the components of the solution he

made? Explain. (2)


(c) Why do blood capillaries have extremely thin

walls? (1)

4. (a) Anjani lowers a pichkari (water gun) into a bucket

full of water and pulls the plunger.

()) Why does the water rise in the pichkari on

pulling the plunger? (2)

(ii) Why would it be slightly difficult to draw

water into the pichkari at higher altitudes?

Give reason. (1)

(b) To keep her soup warm Anita wrapped the

container in which it was kept with a woolen

cloth. Can she apply the same method to keep a

bottle of cold drink cool? Give reason for your

answer, (2)

5. (a) A fisherman is standing on the bank of a water

stream and sees a fish beneath the water surface

in front of him. Should he aim above, below or

directly at the observed fish to make a direct hit?

Explain the reason. (2)

(b) Which of the following wires would be best suited

for carrying large currents and why?

(1)) Wire X with diameter 2mm and length 5cm

(2) Wire Y with diameter 4mm and length 5 cm

(c) A parent amoeba cell divides to form two similar

daughter cells. What is this type of asexual

repreduction called? Name any other organism

which reproduces by the same method. (1)

(a) Classify the following as physical or chemical

changes : (0.5x4)

(i) Formation of rain from clouds

(i) Digestion of food

(ii) Dissolving salt in water

(iv) Glowing of an electric bulb

3

(b) Rehana stopped Juhi from using water to extinguish

the electrical fire. Why might water be a dangerous

choice in this situation? Which type of

extinguisher do you think should be

 used to control  off the electrical fire?

(c) What is the purity of 22K gold?

(a) "When a scientific theory has been supported by

a great deal of scientific evidence, it becomes a

law". Do you agree with this statement? Explain.

(b)_What does AQI (Air Quality Index) indicate? How

would high AQI levels impact our health and the

environment? (2)

(a The graph given below shows the rate of

absorption of chlorophyll a (solid curve) and the

rate of photosynthesis (dotted curve) in green

plants. Answer the following questions on the basis

of the graph -

(i) At what wavelength there is, maxim

absorption of light by chlorophyll a?

(ii) Which of the following colour bands is least

effective in facilitating photosynthesis?

violet-Blue

Green-Yellow

Orange-Red 

(ii) What can you infer about the relation between absorbance of cholorophyll and

rate of photosynthesis between 500 nm

600 nm wavelengths?

(a)What are the differences between internal and

external fertilization of gametes? Do you thínk that

there is any similarity between the seed of a

flowering plant and the fertilized egg of a bird?

Explain. (3)

(b) Draw the dot and cross diagram for CO, and

CaCl,. Name the type of bonding in each case.

(2)

(a) Aluminium is used for packaging of food material

despite it being a reactive metal. Explain the

reason. (2)

(a)_You have two bar magnets. Suggest an activity

to identify the magnet with a greater magnetic

strength. (2)

(b) Alia's mother has to take insulin injections on

a regular basis. In which health condition is

this done? What is the function of Insulin in our

body? (1)

(c)_What is the role őf enzyme pepsin in the digestion

of food? How do the gastric glands ensure

appropriate pH conditions for its functioning?

(2)