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Class 10 - Science
Term-2 Sample Paper - 01
Maximum Marks: 40
Time Allowed: 2 hours
General Instructions:
i. All questions are compulsory.
ii. The question paper has three sections and 15 questions. All questions are compulsory.
iii. Section–A has 7 questions of 2 marks each; Section–B has 6 questions of 3 marks each; and Section–C has 2
case-based questions of 4 marks each.
iv. Internal choices have been provided in some questions. A student has to attempt only one of the
alternatives in such questions.
Section A
1.
2.
3.
4.
5.
i. What is the structural formula of benzene?
ii. Write the correct structural formula of butanoic acid?
Give the atomic number and electronic distribution of :
i) The third alkali metal
ii) The second alkaline earth metal
iii) The first halogen
i. Name the site of implantation and development of baby in human female.
ii. Mention any two benefits of using barrier method during sexual act.
What substances pass
i. from the maternal to the foetal blood?
ii. from the foetal to the maternal blood?
i. In humans, if gene B gives brown eyes and gene b gives blue eyes, what will be the colour of eyes of
the persons having the following combination of genes? (a) Bb (b) bb (c) BB
ii. What do you class this trait of eye colour in human? Explain.
OR
A chimpanzee can hold objects by its hand and an elephant by its trunk. Are these two organs
analogous or homologous? Give reason in support of your answer.
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6. An electron beam enters a magnetic field at right angles to it as shown in the figure.
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i. What will be the direction of force acting on the electron beam?
ii. If a changed particle is moving along the magnetic field line. What will be the magnetic force on
the particle?
7. Rearrange the following according to their trophic levels in a food chain.
Fish, zooplankton, seal, phytoplankton
Section B
8. Table is a part of periodic table
H
.
.
.
.
.
.
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
Use this table and explain why
(a) Li and Na are considered as active metals
(b) Atomic size of Mg is less Than that of Na
(c) Fluorine is more reactive than chlorine.
9. i. Why do covalent molecules have definite shapes?
ii. What is meant by Functional group in the organic compound? Give the Structural formulae of the
functional groups in (i) Acetic acid (ii) Ethyl alcohol.
OR
i. Where do compounds of carbon find applications?
ii. Give three characteristic properties of covalent compounds.
10. In a monohybrid cross, pink coloured flowers are dominant over white coloured flowers. If parent
plants belong to pure breeding dominant trait and pure breeding recessive trait, what will be the
phenotype or morphological feature of F1-generation? If F1 plants are self-fertilised, what would be the
phenotypic ratio or how many dominant and recessive traits will be produced in the progeny? Explain
with an illustration.
11. i. Several electric bulbs designed to be used on a 220V electric supply line are rated 10W. How many
lamps can be connected in parallel with each other across the two wires of 220V line if the
maximum allowable current is 5A?
ii. A heater coil connected to 200 V has a resistance of 80 . If the heater is plugged in for the time t
such that 1 kg of water at 20°C attains a temperature of 60°C. Find the power of the heater and the
heat absorbed by water.
12. If in figure, R1 = 10 , R2 = 40 , R3 = 30 , R4 = 20 , R5 = 60 , and a 12 V battery is connected to the
arrangement. Calculate
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a. the total resistance in the circuit, and
b. the total current flowing in the circuit.
OR
The following circuit diagram shows three resistors 2Ω, 4Ω, RΩconnected to a battery of e.m.f. 2V and
internal resistance 3Ω. A main current of 0.25 A flows through the circuit.
a. What is the P.D. across 4 Ω resistor.
b. Calculate P.D. across the internal resistance of the cell.
13.
i. What is mean by biological magnification?
ii. Will the levels of this magnification be different at different levels of the ecosystem?
Section C
14. Read the Case study followed by 3 questions Part (i) and (ii) are compulsory. However,
an internal choice has been provided in part (iii):
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Refer to the given table regarding results of F2 generation of Mendelian cross.
Plants with round and yellow coloured seeds (P)
315
Plants with round and green coloured seeds (Q)
108
Plants with wrinkled and yellow coloured seeds (R)
101
Plants with wrinkled and green coloured seeds (S)
32
i. What would be the phenotype of F1 generation regarding given data of F2 generation?
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ii. What would be the genotype of parental generation regarding the given result of F2 generation?
iii. If a plant with wrinkled and green coloured seeds (S) is crossed with the plant having wrinkled and
yellow coloured seeds (R), what will be the probable phenotype of offsprings?
OR
What will result when plant YyRr is self-pollinated?
15. Read the Case study followed by 3 questions Part (i) and (ii) are compulsory. However,
an internal choice has been provided in part (iii):
A magnetic field is described by drawing the magnetic field lines. When a small north magnetic pole is
placed in the magnetic field created by a magnet, it will experience a force. And if the north pole is free,
it will move under the influence of the magnetic field. The path traced by a north magnetic pole free to
move under the influence of a magnetic field is called a magnetic field line.
Since the direction of magnetic field line is the direction of force on a north pole, so the magnetic field
lines always begin from the N-pole of a magnet and end on the S-pole of the magnet. Inside the magnet,
however the direction of magnetic field lines is from the S-pole of the magnet to the N-pole of the
magnet. Thus, the magnetic field lines are closed curves. When a small compass is moved along a
magnetic field line, the compass needle always sets itself along the line tangential to it. So, a line drawn
from the south pole of the compass needle to its north pole indicates the direction of the magnetic field
at that point.
i. Do the magnetic field lines intersect? if not why?
ii. A strong bar magnet is placed vertically above a horizontal wooden board. What would be the
magnetic lines of force?
iii. Where do we use Magnetic field lines?
OR
Draw the pattern of magnetic field lines for a bar magnet.
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Class 10 - Science
Term-2 Sample Paper - 01
Solution
Section A
1.
i.
The formula of benzene is C6H6. In all the arms of carbon atoms are occupied.
ii.
The general formula of a carboxylic acid is R-COOH where R is an alkyl group. So, because 'butane'
shows the presence of 4 single-bonded carbon atoms 'oic acid' shows the presence of
group. The formula of butanoic acid is C3H7COOH.
2. i) The third alkali metal is Potassium (K) (Z = 19) = 2, 8, 8, 1
ii) The second alkaline earth metal is Magnesium (Mg) (Z = 12) = 2, 8, 2
iii) The first halogen is Fluorine (F) (Z = 9) = 2, 7
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3.
4.
5.
i. The site of implantation and development of baby in human female is Uterus.
ii. Two benefits of using barrier method during sexual act are:
a. Protection from sexually transmitted diseases.
b. Prevention of pregnancy.
i. Oxygen, nutrients (food and water) pass from maternal to foetal blood.
ii. Carbon dioxide and other waste substances like nitrogenous waste(urea) pass from foetal to
maternal blood.
i. Bb will have brown eyes.
bb will have blue eyes.
BB will have brown eyes.
ii. Eye colour in humans is an inherited trait. These are traits that are present in the DNA of
an organism and are passed on to their progeny.
OR
Trunk of the elephant and hand of a chimpanzee are Analogous organs because they do same function
but have different origin. They both do work of hand for picking various things.
6. i. The direction of force acting on the electron beam will be into the page.
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ii. The angle between velocity and magnetic field is zero. Therefore, magnetic force on the particle is
zero.
7. A food chain always start with producers followed by primary, secondary and tertiary consumer thus,
the food chain will be Phytoplankton, zooplankton, fish, seal.
Section B
8. (a) Both Li and Na are active elements since their atoms have only one electron in their valence shells.
They readily lose this electron to have the configuration of the nearest noble gas element , hence highly
reactive.
(b) Mg is placed after Na is the same period (third). As the atomic size decreases along a period, the size
decreases along a period. The size of Mg is less than that of Na.
(c) Both F and Cl belong to Group 17. Since fluorine is more electronegative than chlorine, it is therefore
more reactive .
Explanation .
chlorine is less reactive than fluorine because the outer electrons in a chlorine atom are further
from the nucleus than the outer electrons in a fluorine atom. It is harder for a chlorine atom to gain
an electron than it is for a fluorine atom.
9.
i. In a covalent molecule, the central atom is surrounded by two types of electron pairs i.e. bond
pairs (shared pair of electrons) and lone pairs (pairs not taking part in bond formation). The
stability of the molecule demands that it should have minimum enthalpy. If the electron pairs
(bond pairs or lone pairs) surrounding the central atom are nearer, they will repel each other,
thereby increasing the enthalpy of the molecule. On the other hand, if the electron pairs are far
apart, the repulsions between them will be less and so the enthalpy of the molecule will be low.
Thus, the electron pairs surrounding the central atom will try to remain as far apart as possible.
As a result the molecule attains minimum enthalpy and maximum stability.So molecule has a
definite shape or geometry.
ii. Functional group is an atom or group of atoms which determines properties of organic compound.
a. -COOH is the functional group present in CH3 COOH (Acetic acid).
b. -OH is the functional group present in C2H5OH (ethyl alcohol).
OR
i. The carbon compounds are being increasingly used as a source of energy, as medicines, colours,
textiles, plastics, food preservatives etc. Wood contains carbon in the form of cellulose.Plastic
contains carbon in long chains called polymers.Steel contains carbon sandwiched between Iron
molecules.Graphite is pure carbon. Diamonds are pure carbon (in a different crystalline structure
than graphite).
ii. Characteristic properties of covalent compounds.
a. Covalent compounds exist as single molecules which are mostly in gaseous
state(hydrogen,oxygen, ammonia).Some of them may be liquid(bromine) and few as
solids(iodine, phosphorus)
b. Covalent compounds have usually low melting and boiling point.Since no ions are present in
the covalent molecules.
c. Covalent compounds are poor conductors of electricity because the current is carried by the
movement of ions.
d. Covalent compounds generally react in molecular form.
e. Covalent compounds are not soluble in water. They dissolve in covalent solvent like carbon
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tetrachloride, benzene etc. (any three)
10. Let the dominant trait be represented by PP.
Let the recessive trait be represented by pp.
Parents PP
pp
F1-generation (pp) (pp) (pp) (pp) i.e. all pink colour flowers, but hybrid. i.e. none are pure homozygous
all the progeny has heterozygous combination, but since, pink is dominant over white, all are pink.
F2-generation when self-fertilised (pp) (pp)
F2-generation gives (PP) (Pp) (Pp) (pp)
Ratio 3 pink colour flowers : 1 white colour flower.
11. i. Let current through each bulb be I.
P = VI, 10 = 220 I
I=
A
Let n such bulbs be connected in series.
Current through n bulbs = 5A
n(current in 1 bult) = 5
n
=5
n = 110
110 such bulbs can be lighted within allowable limit of 5A.
ii.
Power of heater,
Heat absorbed by water,
, C = 4200 J/kgoC]
[
= 168000 J
= 168kJ
12. Suppose we replace the parallel resistors R1 and R2 by an equivalent resistor of resistance, R′. Similarly
we replace the parallel resistors R3, R4 and R5 by an equivalent single resistor of resistance R". Then
using eq.
, we have
Similarly,
that is
Thus, the total resistance, R = R′ + R″ = 18
To calculate the current, we use Ohm’s law, and get
OR
Current in the circuit = 0.25 A
Current through 4Ω wire = 0.25 A
a. P.D. across 4Ω = 0.25 × 4 = 1V
b. P.D. across 3Ω = 0.25 × 3 = 0.75 V
13. The phenomenon in which the harmful pollutants (such as pesticides) enter the food chain and get
concentrated more and more at each successive trophic level of organisms is called biological
magnification.
This can be illustrated by the following example:
Illustration:
In an island in USA after regular DDT spraying for a few years, the population of fish-eating birds
started declining. It was detected that the concentration of DDT had increased 300 times in
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phytoplankton relative to concentration in water. Zooplankton contained about five times greater DDT
than phytoplankton. In different fish, the DDT concentration increased 9 to 40 times relative to the
concentration in zooplankton. Birds showed about 24 times greater DDT concentration relative to that
in fish. Many other persistent pesticides and radionuclides also show biological magnification.
Process of biological magnification
Therefore, we observe that as we go higher and higher in the food chain, the concentration of
pesticides in the body of the organisms gradually increases. For example, in the above example, the
biological magnification of harmful pesticides goes up to 8000 times from water to fish eating birds.
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Section C
14.
i. Plants with round and yellow coloured seeds.
ii. YYRR and yyrr
iii. : Plant with wrinkled and green coloured seeds (S) (genotype rryy) is crossed with plant with
wrinkled and yellow coloured seeds (R) (genotype rrYY or rrYr). If plant with wrinkled and green
coloured seeds (rryy) is crossed with plant having wrinkled and yellow coloured seeds of genotype
rrYY then all plants produced with wrinkled and yellow coloured seeds whereas if plant with
wrinkled and green coloured seeds (rryy) is crossed with plant having wrinkled and yellow
coloured seeds that has genotype rrYy then 50% plants with wrinkled and yellow coloured seeds
and 50% plants with wrinkled and green coloured seeds are produced.
OR
9 : 3 : 3 : 1 ratio of phenotypes only
15. i. No two magnetic field lines are found to cross each other. If two field lines crossed each other, it
would mean that at the point of intersection, the compass needle would point in two directions at
the same time, which is not possible.
ii. The magnetic field and hence the magnetic line of force exist in all the planes all around the
magnet.
iii. The relative strength of the magnetic field is shown by the degree of closeness of the field lines and
the direction of the magnetic field is obtained by tangent to the field lines at the point of intersect.
OR
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