Download Note : (i) All questions are compulsory. (ii) All

Seat No.
2012 ___ ___ 1100
MT -
SCIENCE & TECHNOLOGY (72) - PRELIM II - PAPER - 2 (E)
Time : 2½ Hours
(Pages 4)
Max. Marks : 60
Note :
(i)
All questions are compulsory.
(ii)
All questions carry equal marks.
(iii)
Draw neat and labelled diagrams wherever necessary.
SECTION - A
Q.1. Solve the following :
(i)
7
The phenomenon of splitting of light into its component colours is
................... .
(ii)
When copper powder is heated, ....................... is formed.
(iii)
10% NaCl is known as ....................... .
(iv)
Match the column :
Column A
(v)
Column B
(1) Cylindrical coil of wire
(a)
Safety device
(2) Electric fuse
(b)
Galvanometer
(c)
Solenoid
Find out odd man out :
Armature coil, Brushes, Commutator, Direct current.
(vi)
Name the instrument used to measure P.D. in a circuit.
2 / MT
PAPER - 2
Q.2. Answer the following sub questions :
(i)
6
Define the following :
(a) Ohm’s law.
(b) Joule's law.
(ii)
What is meant by power of accommodation of eye ? State the function
of iris and ciliary muscles.
(iii)
Explain the following reaction with the help of balance chemical
equation : Calcium sulphide reacts with dilute hydrochloric acid.
Q.3. Answer ANY FOUR of the following questions :
(i)
State the characteristics of magnetic lines of force.
(ii)
Explain the zig-zag line in the periodic table.
(iii)
(a) What is the least distance of distinct vision for a normal eye ?
12
(b) An image is formed 5 cm behind a convex mirror of focal length
10 cm. At what distance is the object placed from the mirror ?
(iv)
Find the expression for resistivity of a material.
(v)
What are strong acids and weak acids ? Explain with examples.
Q.4. Answer ANY ONE of the following questions :
(i)
(a) Explain hypermetropia with its correction.
(b) Ram had difficulty in seeing far away objects. What do you think
his eye defect is ? How can it be corrected ?
(ii)
(a) Draw a neat and labelled diagram of electric motor.
(b) State Fleming's left hand rule ?
(c) Distinguish between Electric motor and Electric generator.
5
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PAPER - 2
SECTION - B
Q.5. (A) Fill in the blanks :
(i)
3
The exit of the food from the stomach is regulated by the
....................... .
(ii)
Carbon has ....................... electrons in its outermost orbit, hence
it is ....................... .
(iii)
Pure gold is alloyed with ....................... or ....................... to make
ornaments.
Q.5. (B) Match the following :
4
Column A
Column B
(i)
Herbivores
(a)
Sporangium
(ii)
Carnivores
(b)
Broad intestines
(iii)
Rhizopus
(c)
Carpels of flowers
(iv)
Ovulate pine cones
(d)
Longer small intestine
(e)
Shorter small intestine
Q.6. Answer the following questions :
(i)
Give the IUPAC name of the following :
1. CH3 – CH2 – CH2 – OH.
2. CH3CH = CHCH3.
(ii)
Write the following reaction with the help of chemical equation :
Magnesium reacts with hot water.
(iii)
Write a note on lymph.
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PAPER - 2
Q.7. Answer ANY FOUR of the following questions :
12
(i)
What are hydrocarbons ? Give the classification of hydrocarbons.
(ii)
Write a note on reflex action.
(iii)
What are vestigial organs ? Give examples.
(iv)
Write a note on palaentological evidence.
(v)
To obtain Zn from zinc sulphide two chemical reactions are involved
ZnS
Roasting

A
ZnO
Reduction  Zn +

B
CO
Write the equations for A and B.
Q.8. Answer ANY ONE of the following questions :
(i)
Describe the human female reproductive system.
(ii)
Describe the transport of water in plants.
Best Of Luck

5
Seat No.
2012 ___ ___ 1100
MT -
SCIENCE & TECHNOLOGY (72) - PRELIM II - PAPER - 2 (E)
Time : 2½ Hours
Model Answer Paper
Max. Marks : 60
SECTION - A
A.1.
(i)
(ii)
(iii)
(iv)
(v)
(vi)
A.2.
(i)
(ii)
Solve the following :
The phenomenon of splitting of light into its component colours is
dispersion of light.
When copper powder is heated, copper oxide is formed.
10% NaCl is known as brine.
Column A
Column B
(1) Cylindrical coil of wire
– Solenoid
(2) Electric fuse
– Safety device
Direct current. The rest are the parts of electric motor.
Voltmeter.
Answer the following sub questions :
(a) The electric current flowing in a metallic conductor is directly
proportional to the potential difference across its terminals,
provided physical conditions of the conductor such as length,
area of cross section, temperature and material remain constant.
1
1
1
1
1
1
1
1
(b) The quantity of heat (H) in a conductor of resistance (R) when a
current (I) flows through it for a time (t) is directly proportional to
1. The square of the current.
2. The resistance of the conductor.
3. The time for which the current flows.
1
1. The ability of the lens of adjusting focal length is known as
power of accommodation.
2. The process of focusing the eye at different distances is called
accommodation.
3. This is brought about by a change in curvature of the elastic
lens making it thinner or fatter.
1
1. Iris in human eye controls and regulates the amount of light
entering the eye by contracting and dialating the pupil.
2. Ciliary muscles adjusts the focal length of eye lens by contracting
and relaxing.
1
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PAPER - 2
2
(iii)
1. These motors are used in domestic appliances like mixers,
blenders, refrigerators and washing machines.
2. These motors are used in electric fans, hair dryers, record
players, tape recorders and blowers.
3. These motors are used in electric cars, rolling mills, electric
cranes, electric lifts and electric trains.
A.3.
(i)
Answer ANY FOUR of the following questions :
1. Magnetic lines of force are closed continuous curves. They start
from north pole and ends on south pole.
2. The tangent at any point on the magnetic lines of force gives the
direction of the magnetic field at that point.
3. No two magnetic lines of force can intersect each other.
4. Magnetic lines of force are crowded where the magnetic field is
strong and far from each other where the field is weak.
(ii)
When calcium sulphide reacts with dilute hydrochloric acid to give
calcium chloride and hydrogen sulphide gas is liberated.
CaS (s) + 2HCl )l)

CaCl 2(s)
+ H 2S (g)
Calcium
Hydrochloric acid Calcium chloride
Hydrogen
sulphide
sulphide
3
(iii)
The least distance of distinct vision for a normal eye is 25 cm.
1
Given :
2
Image distance (v) =
Focal length (f)
=
To find : Object distance (u) =
1
1
1
Formula :
+
=
v
u
f
1
1
1
Solution :
+
=
f
v
u

1
u
=
1
f
–
1
v

1
u
=
1
–
10
1
5
1
u
1

u
 u

=
=
=
5 cm
10 cm
?
1 2
10
1
10
– 10cm.
The object is placed in front of the convex mirror at a distance
of 10 cm.
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(iv)
PAPER - 2
1. Resistance of a conductor depends on the length ‘’ and area of
cross section ‘A’ of the conductor
R   andR 

A

R

R =
3
1
A

A
2. Where  is called resistivity of the conductor. It is also called as
specific resistance.
If we put  = 1m and A = 1m2 then
 R = 
3. Thus resistivity of a conductor is defined as the resistance of a
conductor of unit length and unit area of cross - section.
4. The S.I. unit of resistivity is ohm – metre (– m).
(v)
1. An acid which is completely ionized in water and thus produces
a large amount of hydrogen ions is called as strong acid. Eg:
hydrochloric acid is completely ionized in water, so it is a strong
acid.
+
–
Cl(aq)
HCl(aq)
 Η(aq)
+
2. Sulphuric acid and nitric acid are also strong acids as they get
fully ionized in water to produce large amount of hydrogen ions.
3. The word strong refers to the degree of ionization and not to the
concentration of acid. Due to large number of hydrogen ions,
strong acids react rapidly with other substances.
4. They also have a high electrical conductivity.
5. An acid which is partially ionized in water and thus produces a
small amount of hydrogen ions is called as weak acid. Eg: acetic
acid is partially ionized in water, so it is a weak acid.
+
–
CH3COO(aq)
CH3COOH(aq)
 Η(aq)
+
Acetic acid
Hydrogen ion
Acetate ion
6. Sulphurous(H2SO3) acid and carbonic(H2CO3) acid are also weak
acids as they get partially ionized in water to produce small
amount of hydrogen ions.
7. Due to small number of hydrogen ions, weak acids react quite
slowly with other substances.
8. They also have a low electrical conductivity.
A.4.
(i)
Answer ANY ONE of the following questions :
(a) 1. It is the defect in which human eye can see distant objects
clearly but is unable to see nearby objects clearly.
2. The image of near object falls behind retina. Two possible
reasons of hypermetropia are :
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3
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3.
4.
PAPER - 2
(a) Weak action of ciliary muscles causes low converging
power of eye lens.
(b) The distance between eye lens and retina decreases on
account of either shortening of eyeball or flattening of
lens. In this case focal length of the eye lens is too long.
A convex lens of suitable focal length can correct this defect.
The rays coming from nearby object are first converged by
convex lens and then converged by eye lens to retina.
1
(ii)
(b) Ram has myopia. It can be corrected by using concave lens of
suitable focal length.
1
(a) Electric motor.
2
Iron core
B
C
N
S
A
R1
R2
B1
–
+
Battery
–
+
D
B2
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PAPER - 2
(b) Stretch the forefinger, the central finger and the thumb of you
left hand mutually perpendicular to each other. If the forefinger
shows the direction of the field and the central finger shows the
direction of the current, then the thumb will point towards the
direction of the motion of the conductor.
1
(c) Electric motor and Electric generator.
Electric motor
Electric generator
1. A device which converts 1. An electric device which
electrical
energy
into
converts mechanical energy
mechanical energy is called an
into electrical energy is called
electric motor.
an electric generator.
2. Electric motor is based on a 2. It works on the principle of
principle,
when
current
electromagnetic induction.
carrying conductor is placed in
a magnetic field a force acts
on it.
3. It uses electricity.
3. It generates electricity.
1
1
SECTION - B
A.5.
(i)
(ii)
(iii)
A.5.
(A) Fill in the blanks :
The exit of the food from the stomach is regulated by the sphincter
muscle.
Carbon has 4 electrons in its outermost orbit, hence it is tetravalent.
Pure gold is alloyed with silver or copper to make ornaments.
(i)
(ii)
(iii)
(iv)
(B) Match the following
Column A
Herbivores
–
Carnivores
–
Rhizopus
–
Ovulate pine cones
–
:
Column B
Longer small intestine
Shorter small intestine
Sporangium
Carpels of flowers
A.6.
(i)
Answer the following questions :
1. The compound CH3 – CH2 – CH2 – OH is named as propan –1–ol.
2. The position of double bond in the chain is indicated by prefix
the lower number of the carbon atoms between double bonds.
Since the double bond is between C2 and C3 the compound is
but–2–ene.
1
1
1
1
1
1
1
1
1
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PAPER - 2
(ii)
When magnesium reacts with hot water to form magnesium oxide
and hydrogen gas is liberated.
+ 2H 2O(l)  Mg(OH) 2(aq)
+
H 2(g)
Mg (s)
Magnesium
Water
Magnesium hydroxide Hydrogen
2
(iii)
1. When blood flows in the capillaries, some amount of water,
proteins and dissolved solutes are filtered out from the blood
plasma into the tissue spaces. This forms the tissue fluid.
2. This fluid is similar to blood plasma except that it has very less
amount of proteins in it because the capillary wall is impermeable
to plasma proteins.
3. Some amount of this fluid enters small channels called lymph
vessels and the fluid now is known as lymph.
4. This light yellow fluid flows only in one direction that is from
the tissues to the heart.
2
A.7.
(i)
Answer ANY FOUR of the following questions :
Hydrocarbons are the compounds containing carbon and hydrogen
elements only. Hydrocarbons are classified as follows :
3
Hydrocarbons : Compounds containing carbon and hydrogen only.
Open chain hydrocarbons
(Aliphatic)
Closed-chain or ring Or cyclic-hydrocarbons
Alicyclic
C6H12
Cyclohexane
Saturated hydrocarbons
Definition : Hydrocarbons in which
all the four valencies of carbon atoms
are satisfied by single covalent bonds.
Heterocyclic
C4H4O
Furan
Aromatic
C6H6
Benzene
Unsaturated hydrocarbons
Definition : Hydrocarbons in which all the
four valencies of carbon atoms are not
satisfied by single covalent bonds only i.e.
they contain double or triple bonds.
Alkanes
Alkenes
Alkynes
Compounds containing Compounds containing C = C Compounds containing C C
C - C single bonds
double bonds
triple bonds
Eg. CH4 Methane
Eg. C2H4 Ethene or Ethylene Eg. C2H2 Ethyne or
C2H6 Ethane
C3H6 Propene
Acetylene
C3H8 Propane
C4H8 Butene
C3H4 Propyne
C4H10 Butane
C4H6 Butyne
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PAPER - 2
(ii)
1. Any sudden change in response to some happening in the
environment, is called as reflex action.
2. We react to such a situation without thinking about it or without
feeling in control of our reactions.
3. Example : When we touch a vessel containing very hot tea,
immediately the hand is withdrawn.
4. In this case, the nerves that detect pain are connected to the
nerves that bring about the action of the muscle, hence the
action is completed quickly.
5. Nerves from all over the body meeting in a bundle in such a
connection is called as the spinal cord.
6. Hence reflex arcs are formed in the spinal cord, although the
messages reach the brain.
3
(iii)
1. Ill developed structures or structures which are of no use are
sometimes found in both plants and animals. They are referred
to as vestigial organs. The same organ may be functional in one
organism but vestigial in another.
2. Vermiform appendix of man is one such organ. The reason could
be that human ancestors were eating uncooked food with
considerable amount of cellulose in it. The normal function of
caecum and appendix in mammals is the digestion of cellulose.
3. Man shows a number of other vestigial organs. About 100 have
been named. A few examples are ear muscles, wisdom teeth,
plica semilunaris (representing nictitating membrane of the eye),
coccyx (reduced tail) etc.
4. In plants, the scale like leaves on the Indian pipe, a plant which
has lost its chlorophyll and became saprophytic in nature, are
vestigial.
5. There are certain flowers in which stamens do not bear anthers.
3
(iv)
1. Palaentology is the study of fossils.
2. The process of fossilization takes a very long period of time. In
order to study the fossil, the land is excavated.
3. Fossils are collected from different levels of depths. A systematic
study of these fossils and its occurance revealed that the deepest
layers were found to have fossils of invertebrates.
4. In layers above them were found prehistoric fish-like animals,
amphibians, reptiles, birds and mammals respectively in that
order.
5. This suggests that perhaps this was the oder in which the
animals appeared on the earth.
3
(v)
When zinc sulphide is heated strongly in excess of air, it decomposes
to give zinc oxide and sulphur dioxide gas is liberated.
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ZnS (s)
+
3O 2(g)



Roasting
2ZnO (s) +
PAPER - 2
2SO 2(g)
Zinc sulphide
Zinc oxide Sulphur dioxide
When zinc oxide is treated with carbon as a reducing agent, zinc
oxide is reduced to zinc and carbon is oxidized to carbon monoxide.
ZnO (s) + C (s)

Zn (s)
+ CO (g)
Zinc oxide Carbon
Zinc
Carbon monoxide
A.8.
(i)
Answer ANY ONE of the following questions :
The human female reproductive system consists of main reproductive
organs like vagina, uterus, oviduct and ovaries.
1. Vagina :
(a) It is a muscular tube that extends from the vaginal opening
to the uterus.
(b) It provides the route for the menstrual blood to leave the
body during menstruation.
(c) It is a pathway through which the sperms enter into the
woman’s body and is a pathway through which a baby comes
out of the woman’s body during childbirth.
2. Uterus : Uterus is a muscular organ. Due to strong muscles and
ability to expand and contract, the uterus can accomodate a
growing foetus and push the baby during labour.
3. Overies : Ovaries are two oval shaped organs that lie to the
upper right and left of the uterus. They develop and release
eggs into the oviduct. They secrete hormone oestrogen which
brings about changes in girls during puberty. When a baby girl is
born the ovaries already contain thousands of immature eggs
which remain inactive till maturity. On reaching puberty, a
woman’s ovaries usually release one egg each month.
(ii)
The transport of water in plants takes place because of :
1. Root pressure
2.
Transpiration pull.
1. Root pressure :
(a) Root cells are in contact with water and minerals present
in the soil. Due to the difference in concentration, water
molecules and minerals enter the cells of roots.
(b) The cells at the surface become turgid and exert pressure
on neighbouring cells called as root pressure.
(c) The minerals and water reach the root xylem and is pushed
further and further to eliminate this difference.
(d) This steady movement creates a column of water that is
steadily pushed upwards.
(e) However, this pressure is not enough to move the water up in
tall trees, though it is adequate in small plants like herbs or
shrubs or even small trees.
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PAPER - 2
2. Transpiration pull :
(a) The loss of water in the form of water vapour from the aerial
parts of the plants, like stomata of leaves, is known as
transpiration.
(b) Evaporation of water from the leaves to the atmosphere
results in a decrease in the water potential of the cells.
(c) The water which is lost is replaced by the water from the
xylem vessels in the leaf. Gradually it creates suction which
pulls water from xylem cells of roots which in turn absorb
more water.
(d) Thus the pull due to transpiration helps in absorption and
movement of water and dissolved minerals in tall plants
during the day when stomata are open, while effect of root
pressure is important during night.
