Class- X( Mathematics -Standard) Sample Question Paper Session- 2023-24

 Class- X Session- 2023-24


Subject- Mathematics -Standard


Sample Question Paper




Time Allowed: 3 Hours Maximum Marks: 80

General Instructions:

1. This question paper contains two parts A and B.

2. Both Part A and Part B have internal choices.

Part – A:

1. It consists three sections- I and II.

2. Section I has 16 questions of 1 mark each. Internal choice is provided in 5 questions.

3. Section II has 4 questions on case study. Each case study has 5 case-based sub-parts. An

examinee is to attempt any 4 out of 5 sub-parts.

Part – B:

1. Question No 21 to 26 are Very short answer Type questions of 2 mark each,

2. Question No 27 to 33 are Short Answer Type questions of 3 marks each

3. Question No 34 to 36 are Long Answer Type questions of 5 marks each.

4. Internal choice is provided in 2 questions of 2 marks, 2 questions of 3 marks and 1 question of 5

marks.

Question

No.

======================================================================

Part-A Marks allocated

Section-I

Section I has 16 questions of 1 mark each. Internal choice is provided in 5 questions.


1> If xy=180 and HCF(x,y)=3, then find the LCM(x,y).

OR

The decimal representation of 14587

2>

1 × 5

4

will terminate after how many decimal


places?


1


2 If the sum of the zeroes of the quadratic polynomial 3x2


-kx+6 is 3, then find


the value of k.


1


Page 2 of 14


3. > For what value of k, the pair of linear equations 3x+y=3 and 6x+ky=8 does not have a solution.


4>. If 3 chairs and 1 table costs Rs. 1500 and 6 chairs and 1 table costs Rs.2400. Form linear equations to represent this situation.

5. >Which term of the A.P. 27, 24, 21,.....is zero?

OR

In an Arithmetic Progression, if d= - 4, n=7,an=4, then find a.

6. For what values of k, the equation 9x2+6kx+4=0 has equal roots?

7. Find the roots of the equation x2+7x+10=0

OR

For what value(s) of ‘a’ quadratic equation 30 ax 2 − 6x + 1 = 0 has no real roots?

8. If PQ=28cm, then find the perimeter of ∆PLM 1

9. If two tangents are inclined at 60 ̊ are drawn to a circle of radius 3cm then

find length of each tangent.

OR

PQ is a tangent to a circle with centre O at point P. If ∆OPQ is an isosceles

triangle, then find ∠OQP.

10. In the ∆ABC, D and E are points on side AB and AC respectively such that

DE II BC. If AE=2cm, AD=3cm and BD=4.5cm, then find CE.

11. In the figure, if B1, B2, B3,...... and A1,A2, A3,..... have been marked at

equal distances. In what ratio C divides AB?

12. Sin A + Cos B = 1, A = 30° and B is an acute angle, then find the value of B. 1

13. If x=2sin2Ɵ and y=2cos2Ɵ+1, then find x+y 1

14. In a circle of diameter 42cm,if an arc subtends an angle of 60 ̊ at the centre

where ∏=22/7, then what will be the length of arc.

15. 12 solid spheres of the same radii are made by melting a solid metallic

cylinder of base diameter 2cm and height 16cm. Find the diameter of the

each sphere.

16. Find the probability of getting a doublet in a throw of a pair of dice.

Find the probability of getting a black queen when a card is drawn at random

from a well-shuffled pack of 52 cards.

Section-II

Case study based questions are compulsory. Attempt any four sub

parts of each question. Each subpart carries 1 mark

17. Case Study based-1

SUN ROOM

The diagrams show the plans for a sun room. It will be built onto the wall of a

house. The four walls of the sunroom are square clear glass panels. The roof

is made using

• Four clear glass panels, trapezium in shape, all the same size

• One tinted glass panel, half a regular octagon in shape


(a) Refer to Top View


Find the mid-point of the segment joining the points J (6, 17) and I (9, 16).

(i) (33/2,15/2)

(ii) (3/2,1/2)

(iii)(15/2,33/2)

(iv) (1/2,3/2)

(b) Refer to Top View

The distance of the point P from the y-axis is

(i) 4

(ii) 15

(iii) 19

(iv) 25

(c) Refer to Front View


The distance between the points A and S is

(i) 4

(ii) 8

(iii)16

(iv)20


1


(d) Refer to Front View


Find the co-ordinates of the point which divides the line segment joining the

points A and B in the ratio 1:3 internally.

(i) (8.5,2.0)

(ii) (2.0,9.5)

(iii) (3.0,7.5)

(iv) (2.0,8.5)


1


(e) Refer to Front View


If a point (x,y) is equidistant from the Q(9,8) and S(17,8),then

(i) x+y=13

(ii) x-13=0

(iii) y-13=0

(iv)x-y=13


1


18. Case Study Based- 2


SCALE FACTOR AND SIMILARITY

SCALE FACTOR

A scale drawing of an object is the same shape as the object but a different

size.

The scale of a drawing is a comparison of the length used on a drawing to

the length it represents. The scale is written as a ratio.

SIMILAR FIGURES

The ratio of two corresponding sides in similar figures is called the scale

factor.


Scale factor =


length in image

corresponding length in object


If one shape can become another using Resizing then the

shapes are Similar

Th


Page 6 of 14


Th


Rotation or Turn


Reflection or Flip


Translation or Slide


Hence, two shapes are Similar when one can become the other after

a resize, flip, slide or turn.


(a) A model of a boat is made on the scale of 1:4. The model is 120cm long. The

full size of the boat has a width of 60cm. What is the width of the scale

model?


(i) 20 cm

(ii) 25 cm

(iii) 15 cm

(iv)240 cm


1


Page 7 of 14


(b) What will effect the similarity of any two polygons?


(i) They are flipped horizontally

(ii)They are dilated by a scale factor

(iii)They are translated down

(iv)They are not the mirror image of one another


1


(c) If two similar triangles have a scale factor of a: b. Which statement regarding


the two triangles is true?

(i)The ratio of their perimeters is 3a : b

(ii)Their altitudes have a ratio a:b

(iii)Their medians have a ratio a

2

: b

(iv)Their angle bisectors have a ratio a2

: b

2


1


(d) The shadow of a stick 5m long is 2m. At the same time the shadow of a tree


12.5m high is


(i)3m

(ii)3.5m

(iii)4.5m

(iv)5m


1


(e) Below you see a student's mathematical model of a farmhouse roof with

measurements. The attic floor, ABCD in the model, is a square. The beams

that support the roof are the edges of a rectangular prism, EFGHKLMN. E is

the middle of AT, F is the middle of BT, G is the middle of CT, and H is the

middle of DT. All the edges of the pyramid in the model have length of 12 m.

1


Page 8 of 14


What is the length of EF, where EF is one of the horizontal edges of the

block?

(i)24m

(ii)3m

(iii)6m

(iv)10m


19. Case Study Based- 3


Applications of Parabolas-Highway Overpasses/Underpasses

A highway underpass is parabolic in shape.


Parabola

A parabola is the graph that

results from p(x)=ax

2+bx+c

Parabolas are symmetric

about a vertical line known

as the Axis of Symmetry.

The Axis of Symmetry runs

through the maximum or

minimum point of the

parabola which is called the


Page 9 of 14


Vertex


(a) If the highway overpass is represented by x2–2x –8. Then its zeroes are


(i) (2,-4)

(ii) (4,-2)

(iii) (-2,-2)

(iv) (-4,-4)


(b) The highway overpass is represented graphically.


Zeroes of a polynomial can be expressed graphically. Number of zeroes of

polynomial is equal to number of points where the graph of polynomial

(i) Intersects x-axis

(ii) Intersects y-axis

(iii) Intersects y-axis or x-axis

(iv)None of the above


Page 10 of 14


(c) Graph of a quadratic polynomial is a


(i) straight line

(ii) circle

(iii)parabola

(iv)ellipse


(d) The representation of Highway Underpass whose one zero is 6 and sum of


the zeroes is 0, is

(i)x

2 – 6x + 2

(ii) x

2 – 36

(iii)x

2 – 6

(iv)x

2 – 3


(e) The number of zeroes that polynomial f(x) = (x – 2)2 + 4 can have is:


(i)1

(ii) 2

(iii) 0

(iv) 3


20. Case Study Based- 4


100m RACE

A stopwatch was used to

find the time that it took a

group of students to run 100

m.


Time

(in sec)


0-20 20-40 40-60 60-80 80-100


No. of

students


8 10 13 6 3


Page 11 of 14


(a) Estimate the mean time taken by a student to finish the race.


(i)54

(ii)63

(iii)43

(iv)50


(b) What wiil be the upper limit of the modal class ?


(i)20

(ii)40

(iii)60

(iv)80


(c) The construction of cummulative frequency table is useful in determining the


(i)Mean

(ii)Median

(iii)Mode

(iv)All of the above


(d) The sum of lower limits of median class and modal class is


(i)60

(ii)100

(iii)80

(iv)140


(e) How many students finished the race within 1 minute?


(i)18

(ii)37

(iii)31

(iv)8


Part –B


All questions are compulsory. In case of internal choices, attempt any

one.


21. 3 bells ring at an interval of 4,7 and 14 minutes. All three bell rang at 6 am,


when the three balls will the ring together next?


2


22. Find the point on x-axis which is equidistant from the points (2,-2) and (-4,2)


OR


2


Page 12 of 14


P (-2, 5) and Q (3, 2) are two points. Find the co-ordinates of the point R on

PQ such that PR=2QR


23. Find a quadratic polynomial whose zeroes are 5-3√2 and 5+3√2. 2

24. Draw a line segment AB of length 9cm. With A and B as centres, draw

circles of radius 5cm and 3cm respectively. Construct tangents to each circle

from the centre of the other circle.


2


25. If tanA=3/4, find the value of 1/sinA+1/cosA


OR

If √3 sinƟ-cosƟ=0 and 0 ̊<Ɵ <90 ̊, find the value of Ɵ


2


26. In the figure, quadrilateral ABCD is circumscribing a circle with centre O


and AD⊥AB. If radius of incircle is 10cm, then the value of x is


2


27.. Prove that 2-√3 is irrational, given that √3 is irrational. 3

28. If one root of the quadratic equation 3x2+px+4=0 is 2/3, then find the value


of p and the other root of the equation.

OR

The roots α and β of the quadratic equation x2


-5x+3(k-1)=0 are such that α-

β=1. Find the value k.


3


Page 13 of 14


29. In the figure, ABCD is a square of side 14 cm. Semi-circles are drawn with

each side of square as diameter. Find the area of the shaded region.


3


30. The perimeters of two similar triangles are 25cm and 15cm respectively. If

one side of the first triangle is 9cm, find the length of the corresponding side

of the second triangle.


OR


In an equilateral triangle ABC, D is a point on side BC such that BD = 1/3

BC. Prove that 9 AD2 = 7 AB2


3


31. The median of the following data is 16. Find the missing frequencies a and b, if the total of the frequencies is 70.

Class 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40

Frequency 12 a 12 15 b 6 6 4 3

32.If the angles of elevation of the top of the candle from two coins distant ‘a’

cm and ‘b’ cm (a>b) from its base and in the same straight line from it are

30 ̊ and 60 ̊, then find the height of the candle.

Section V

33. The mode of the following data is 67. Find the missing frequency x.

Class 40-50 50-60 60-70 70-80 80-90 Frequency 5 x 15 12 7

34. The two palm trees are of equal heights and are standing opposite each

other on either side of the river, which is 80 m wide. From a point O

between them on the river the angles of elevation of the top of the trees

are 60° and 30°, respectively. Find the height of the trees and the

distances of the point O from the trees.

OR

The angles of depression of the top and bottom of a building 50 meters

high as observed from the top of a tower are 30 ̊ and 60 ̊ respectively.

Find the height of the tower, and also the horizontal distance between the

building and the tower.

35. Water is flowing through a cylindrical pipe of internal diameter 2cm, into a

cylindrical tank of base radius 40 cm at the rate of 0.7m/sec. By how

much will the water rise in the tank in half an hour?

36. A motorboat covers a distance of 16km upstream and 24km downstream

in 6 hours. In the same time it covers a distance of 12 km upstream and

36km downstream. Find the speed of the boat in still water and that of the

stream.

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Best of Luck



Science-X (Latest Sample Question Paper )


Science-X (Latest Sample Question Paper)

Science Class X


Time: 3 Hours Maximum Marks: 80

General Instructions:

(i) The question paper comprises four sections A, B, C and D. There are 36 questions in
the question paper. All questions are compulsory.
(ii) Section–A - question no. 1 to 20 - all questions and parts thereof are of one mark each.
These questions contain multiple choice questions (MCQs), very short answer
questions and assertion - reason type questions. Answers to these should be given in
one word or one sentence.
(iii) Section–B - question no. 21 to 26 are short answer type questions, carrying 2 marks
each. Answers to these questions should in the range of 30 to 50 words.
(iv) Section–C - question no. 27 to 33 are short answer type questions, carrying 3 marks
each. Answers to these questions should in the range of 50 to 80 words.
(v) Section–D – question no. - 34 to 36 are long answer type questions carrying 5 marks
each. Answer to these questions should be in the range of 80 to 120 words.
(vi) There is no overall choice. However, internal choices have been provided in some
questions. A student has to attempt only one of the alternatives in such questions.
(vii) Wherever necessary, neat and properly labeled diagrams should be drawn.
==============================================================
SECTION A

No. Questions Marks
1 List any two observations when Ferrous Sulphate is heated in a dry test tube?

OR

Identify the products formed when 1 mL of dil. Hydrochloric acid is added to
1g of Sodium metal?

2 Write the chemical name and chemical formula of the salt used to remove
permanent hardness of water.

3 Which of the following is not observed in a homologous series? Give reason
for your choice.
a) Change in chemical properties
b) Difference in -CH2 and 14u molecular mass
c) Gradation in physical properties
d) Same functional group

1

4>Why does the Sun appear white at noon? 

5> Both a spherical mirror and a thin spherical lens have a focal length of (-)15cm. What type of mirror and lens are these?



6 The image formed by a concave mirror is observed to be real, inverted and larger than the object. Where is the object placed?
OR

Name the part of a lens through which a ray of light passes without suffering any deviation.

7> In the arrangement shown in figure there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted in the circuit. Later the key is inserted and then removed shortly after.

What are the two observations that can be noted from the galvanometer reading?


8> Draw the magnetic field lines around a straight current carrying conductor. 

9> Two unequal resistances are connected in parallel. If you are not provided with
any other parameters (eg. numerical values of I and R), what can be said about
the voltage drop across the two resistors?
OR

Some work is done to move a charge Q from infinity to a point A in space. The
potential of the point A is given as V. What is the work done to move this
charge from infinity in terms of Q and V?




10 Veins are thin walled and have valves. Justify. 1
11 How is the wall of small intestine adapted for performing the function of
absorption of food?

OR

Out of a goat and a tiger, which one will have a longer small intestine? Justify
your answer.

1

12 Explain how ozone being a deadly poison can still perform an essential
function for our environment.

OR

Give reason why a food chain cannot have more than four trophic levels.

1

3
13 State the role of pancreas in digestion of food. 1
For question numbers 14, 15 and 16, two statements are given- one labeled Assertion (A) and the
other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c)
and (d) as given below:
a) Both A and R are true, and R is correct explanation of the assertion.
b) Both A and R are true, but R is not the correct explanation of the assertion.
c) A is true, but R is false.
d) A is false, but R is true.
14 Assertion: After white washing the walls, a shiny white finish on walls is
obtained after two to three days.
Reason: Calcium Oxide reacts with Carbon dioxide to form Calcium
Hydrogen Carbonate which gives shiny white finish.

1

15 Assertion: Food chain is responsible for the entry of harmful chemicals in our
bodies.
Reason: The length and complexity of food chains vary greatly.

OR

Assertion: Greater number of individuals are present in lower trophic levels.
Reason: The flow of energy is unidirectional.

1

16 Assertion: A geneticist crossed a pea plant having violet flowers with a pea
plant with white flowers, he got all violet flowers in first generation.
Reason: White colour gene is not passed on to next generation.

1

Answer Q. No 17 - 20 contain five sub-parts each. You are expected to answer any four sub-
parts in these questions.

17 Read the following and answer any four questions from 17 (i) to 17 (v)
All living cells require energy for various activities. This energy is available by
the breakdown of simple carbohydrates either using oxygen or without using
oxygen.

1x4

(i) Energy in the case of higher plants and animals is obtained by
a) Breathing
b) Tissue respiration
c) Organ respiration
d) Digestion of food
(ii) The graph below represents the blood lactic acid concentration of an athlete
during a race of 400 m and shows a peak at point D.

4

Lactic acid production has occurred in the athlete while running in the 400
m race. Which of the following processes explains this event?
a) Aerobic respiration
b) Anaerobic respiration
c) Fermentation
d) Breathing
(iii) Study the graph below that represents the amount of energy supplied with
respect to the time while an athlete is running at full speed.

Choose the correct combination of plots and justification provided in the
following table.

5

Plot A Plot B Justification
a) Aerobic Anaerobic Amount of energy is low and inconsistent

in aerobic and high in anaerobic

b) Aerobic Anaerobic Amount of energy is high and consistent

in aerobic and low in anaerobic

c) Anaerobic Aerobic Amount of energy is high and consistent

in aerobic and low in anaerobic

d) Anaerobic Aerobic Amount of energy is high and inconsistent

in anaerobic and low in aerobic
(iv) The characteristic processes observed in anaerobic respiration are
i) presence of oxygen
ii) release of carbon dioxide
iii) release of energy
iv) release of lactic acid
a) i) ,ii) only
b) i), ii), iii) only
c) ii), iii), iv) only
d) iv) only
(v) Study the table below and select the row that has the incorrect information.

Aerobic Anaerobic
a) Location Cytoplasm Mitochondria

b) End Product CO2 and H20 Ethanol and CO2

c) Amount of ATP High Low
d) Oxygen Needed Not needed

18 Read the following and answer any four questions from 18 (i) to 18 (v).
Metallic Character
The ability of an atom to donate electrons and form positive ion (cation) is
known as electropositivity or metallic character. Down the group, metallic
character increases due to increase in atomic size and across the period, from
1x 4

6

left to right electropositivity decreases due to decrease in atomic size.
Non-Metallic Character
The ability of an atom to accept electrons to form a negative ion (anion) is
called non-metallic character or electronegativity. The elements having high
electro-negativity have a higher tendency to gain electrons and form anion.
Down the group, electronegativity decreases due to increase in atomic size and
across the period, from left to right electronegativity increases due to decrease
in atomic size.

18 (i) Which of the following correctly represents the decreasing order of metallic
character of Alkali metals plotted in the graph?
a) Cs>Rb>Li>Na>K
b) K>Rb>Li>Na>Cs
c) Cs>Rb>K>Na>Li
d) Cs>K>Rb>Na>Li

18 (ii) Hydrogen is placed along with Alkali metals in the modern periodic table
though it shows non-metallic character
a) as Hydrogen has one electron & readily loses electron to form negative
ion
b) as Hydrogen can easily lose one electron like alkali metals to form
positive ion
c) as Hydrogen can gain one electron easily like Halogens toform
negative ion
d) as Hydrogen shows the properties of non-metals
18 (iii) Which of the following has highest electronegativity?

a) F
b) Cl
c) Br
d) I

7

18 (iv) Identify the reason for the gradual change in electronegativity in halogens
down the group.
a) Electronegativity increases down the group due to decrease in atomic
size
b) Electronegativity decreases down the group due to decrease in
tendency to lose electrons
c) Electronegativity decreases down the group due to increase in atomic
radius/ tendency to gain electron decreases
d) Electronegativity increases down the group due to increase in forces of
attractions between nucleus & valence electrons

18 (v) Which of the following reason correctly justifies that “Fluorine (72pm) has
smaller atomic radius than Lithium (152pm)”?
a) F and Li are in the same group. Atomic size increases down the group
b) F and Li are in the same period. Atomic size increases across the
period due to increase in number of shells
c) F and Li are in the same group. Atomic size decreases down the group
d) F and Li are in the same period and across the period atomic size/radius
decreases from left to right.

19 Read the following and answer any four questions from 19 (i) to 19 (v)
Sumati wanted to see the stars of the night sky. She knows that she needs a
telescope to see those distant stars. She finds out that the telescopes, which are
made of lenses, are called refracting telescopes and the ones which are made of
mirrors are called reflecting telescopes.

So she decided to make a refracting telescope. She bought two lenses, L1 and
L2. out of which L1 was bigger and L2 was smaller. The larger lens gathers and
bends the light, while the smaller lens magnifies the image. Big, thick lenses
are more powerful. So to see far away, she needed a big powerful lens.
Unfortunately, she realized that a big lens is very heavy.
Heavy lenses are hard to make and difficult to hold in the right place. Also
1x 4

8

since the light is passing through the lens, the surface of the lens has to be
extremely smooth. Any flaws in the lens will change the image. It would be
like looking through a dirty window.
19 (i) Based on the diagram shown, what kind of lenses would Sumati need to make
the telescope?
a) Concave lenses
b) Convex lenses
c) Bifocal lenses
d) Flat lenses

19 (ii) If the powers of the lenses L1 and L2 are in the ratio of 4:1, what would be the
ratio of the focal length of L1 and L2?
a) 4:1
b) 1:4
c) 2:1
d) 1:1

19 (iii) What is the formula for magnification obtained with a lens?
a) Ratio of height of image to height of object
b) Double the focal length.
c) Inverse of the radius of curvature.
d) Inverse of the object distance.

19 (iv) Sumati did some preliminary experiment with the lenses and found out that the
magnification of the eyepiece (L2) is 3. If in her experiment with L2 she found
an image at 24 cm from the lens, at what distance did she put the object?
a) 72 cm
b) 12 cm
c) 8 cm
d) 6 cm

19 (v) Sumati bought not-so-thick lenses for the telescope and polished them. What
advantages, if any, would she have with her choice of lenses?
a) She will not have any advantage as even thicker lenses would give
clearer images.
b) Thicker lenses would have made the telescope easier to handle.
c) Not-so-thick lenses would not make the telescope very heavy and also
allow considerable amount of light to pass.
d) Not-so-thick lenses will give her more magnification.

9

20 Read the following and answer any 4 questions from 20 (i) to 20 (v).
A solenoid is a long helical coil of wire through which a current is run in
order to create a magnetic field. The magnetic field of the solenoid is the
superposition of the fields due to the current through each coil. It is nearly
uniform inside the solenoid and close to zero outside and is similar to the field
of a bar magnet having a north pole at one end and a south pole at the other
depending upon the direction of current flow. The magnetic field produced in
the solenoid is dependent on a few factors such as, the current in the coil,
number of turns per unit length etc.
The following graph is obtained by a researcher while doing an experiment to
see the variation of the magnetic field with respect to the current in the
solenoid.
The unit of magnetic field as given in the graph attached is in milli-Tesla (mT)
and the current is given in Ampere.

4

20 (i) What type of energy conversion is observed in a linear solenoid?

a. Mechanical to Magnetic
b. Electrical to Magnetic
c. Electrical to Mechanical
d. Magnetic to Mechanical

20 (ii) What will happen if a soft iron bar is placed inside the solenoid?
a. The bar will be electrocuted resulting in short-circuit.
b. The bar will be magnetised as long as there is current in the circuit.
c. The bar will be magnetised permanently.
d. The bar will not be affected by any means.

20 (iii) The magnetic field lines produced inside the solenoid are similar to that of ...

a. a bar magnet

10

b. a straight current carrying conductor
c. a circular current carrying loop
d. electromagnet of any shape

20 (iv) After analysing the graph a student writes the following statements.

I. The magnetic field produced by the solenoid is inversely proportional
to the current.
II. The magnetic field produced by the solenoid is directly proportional to
the current.
III. The magnetic field produced by the solenoid is directly proportional to
square of the current.
IV. The magnetic field produced by the solenoid is independent of the
current.
Choose from the following which of the following would be the correct
statement(s).
a. Only IV
b. I and III and IV
c. I and II
d. Only II

20 (v) From the graph deduce which of the following statements is correct.

a. For a current of 0.8A the magnetic field is 13 mT
b. For larger currents, the magnetic field increases non-linearly.
c. For a current of 0.8A the magnetic field is 1.3 mT
d. There is not enough information to find the magnetic field
corresponding to 0.8A current.
SECTION B

21 Bile juice does not have any digestive enzyme but still plays a significant role
in the process of digestion. Justify the statement.
OR

In birds and mammals the left and right side of the heart are separated. Give
reasons.

22 State the events occurring during the process of photosynthesis. Is it essential
that these steps take place one after the other immediately?

23 Give a test that can be used to confirm the presence of carbon in a compound.
With a valency of 4, how is carbon able to attain noble gas configuration in its
compounds?
OR
The number of carbon compounds is more than those formed by all other
elements put together. Justify the statement by giving two reasons.

24 The following observations were made by a student on treating four metals P,
Q, R and S with the given salt solutions:

Sample MgSO4(aq) Zn(NO3)2(aq) CaSO4(aq) Na2SO4(aq)
    No reaction Reaction occurs Reaction occurs
No reaction Q Reaction occurs Reaction occurs
Reaction occurs Reaction occurs
R No Reaction Reaction Occurs
No Reaction No Reaction
S No Reaction No Reaction No Reaction No Reaction

Based on the above observations:
(a) Arrange the given samples in the increasing order of reactivity
(b) Write the chemical formulae of products formed when Q reacts with
CuSO4 solution.

25 A student observes the above phenomenon in the lab as a white light passes
through a prism. Among many other colours, he observed the position of the two colours Red and Violet.
What is the phenomenon called? What is the reason for the violet light to bend more than the red light?

26 A student has two resistors- 2 Ω and 3 Ω. She has to put one of them in place
of R2 as shown in the circuit. The current that she needs in the entire circuit is
exactly 9A. Show by calculation which of the two resistors she should choose.

Section C

27 After self-pollination in pea plants with round, yellow seeds, following types
of seeds were obtained by Mendel:
Seeds Number
Round, yellow 630
Round, green 216
Wrinkled, yellow 202
Wrinkled, green 64
Analyse the result and describe the mechanism of inheritance which explains
these results.

OR

In humans, there is a 50% probability of the birth of a boy and 50 %
probability that a girl will be born. Justify the statement on the basis of the
mechanism of sex-determination in human beings.

3

28 Plastic cups were used to serve tea in trains in early days- these could be
returned to the vendors, cleaned and reused. Later,Kulhads were used instead
of plastic cups. Now, paper cups are used for serving tea.
What are the reasons for the shift from Plastic to Kulhads and then finally to paper cups?

29 Explain where and how urine is produced?
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Best of luck for CBSE Board Exam










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