GOODWILL EDUCATION
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Prepared by anoop malviya
CHAPTER – 1
1.
Write the molecular formula of
benzene and state the number of double bonds in its structure.
2.
Write the name and formula of the
second member of the carbon compounds having functional group – OH.
3.
Write the name and formula of the
2nd member of the series of carbon compounds whose general formula is CnH2n+1OH.
4.
Write the electron dot structure of
ethane molecule (C2H6).
5.
Draw the structure of the hexanal
molecule, C5H11CHO.
6.
State two characteristic features
of carbon which when put together give rise to large number of carbon
compounds.
7.
Name the compound formed when
ethanol is warmed with ethanoic acid in the presence of a few drop of cone. H2SO4.
8.
What would be the electron dot
structure of carbon dioxide which has formula CO2?
9.
Why is the conversion of ethanol to
ethanoic acid an oxidation reaction?
10.
Write the name and molecular formula of an
organic compound having its name suffixed with ‘-ol’ and having two carbon
atoms in the molecule. With the help of a balanced chemical equation indicate
what happens when it is heated with excess of cone. H2SO4.
11.
Write the names and molecular formula of two
organic compounds having functional group suffixed as ‘-oic acid’. With the
help of a balanced chemical equation and explain what happens when any one of
them reacts with sodium hydroxide.
12.
What is a homologous series? Which two of the
following organic compounds belong to the same homologous? C2H6,
C2H6O, C2H6O2, CH4O.
13.
Write IUPAC names of (i) CH3COH2CH3 (ii) CH3-CH(OH)-CH3 (iii) HCOOH (iv)
CH3COOCH3
14.
How many structural isomers can you draw for
pentane?
15.
How can ethanol and ethanoic acid be
differentiated on the basis of their physical and chemical properties?
16.
Why does micelle formation take place when
scap is added to water? Will a micelle be formed in other solvents like ethanol
also?
17.
Explain the mechanism of the cleaning action
of soaps.
18.
What are oxidizing agents? Give an example.
19.
Why homologous series
of carbon compounds are so called? Write chemical formula of two consecutive
members of a homologous series and state the part of these compounds that
determines their (i) physical properties, and (ii) chemical properties.
20.
(a) Differentiate between alkanes and alkenes.
Name and draw the structure of one member of each.
(b)
Alkanes generally burn with clean flame. Why?
21.
What
happens when:
a) Ethanol
is burnt in air,
b) Ethanol
is heated with excess conc. H2SO4 at 443 K,
c) A
piece of sodium is dropped into ethanol?
21.
Complete the following equations:
Complete the following equations:
a) 
CH3COOC2H5
CH3COOC2H5
b) 
CH3COOH +
NaHCO3
CH3COOH +
NaHCO3
c)
CH2 + CI2
CH2 + CI2
22.
Write one chemical equation to represent each
of the following types of reactions of organic substances:
a) Esterification
b) Saponification
c) Substitution
23.
(a) What are isomers? Draw the structures of
two isomers of butane, C4H10.
(b) Differentiate between alkenes and alkynes.
24.
What is ethanol? State
its two properties. What happens when it is heated with excess of conc. H2SO4
at 443 K? what role does conc. H2SO4 play in this
reaction? Write chemical equation of the reaction involved and the structural
formula of the main product formed.
25.
Give reasons for the following observations:
(a) The
element carbon forms a very large number of compounds.
(b) Air
holes of a gas burner have to be adjusted when the heated vessels get blackened
by the flame.
(c) Use
of synthetic detergents causes pollution of water.
26.
(a) Give a chemical
test to distinguish between saturated and unsaturated hydrocarbons.
(b)
(i) Name the products formed when ethanol burns in air.
(ii)
What two forms of energy are liberated on burning alcohol?
(c) Why is the reaction
between methane and chlorine considered a substitution reaction?
27.
(a) Why are covalent
compounds generally poor conductors of electricity?
(b) Name the following compound.
28.
An organic compound ‘X’
on heating with cone. H2SO4 forms a compound ‘Y’ which on
addition of one molecule of hydrogen in the presence of nickel forms a compound
‘Z’. one molecule of compound ‘Z’ on combustion forms two molecules of CO2
and three molecules of H2O. Identify giving reasons the compounds
‘X’, ‘Y’ and ‘Z’. write the chemical equations for all the chemical reactions
involved.
29.
Give two examples of covalent compounds which
you have studied. State any four properties in which covalent compounds differ
from ionic compounds.
30.
Give reasons for the following:
(i)
Element carbon forms compounds mainly by
covalent bonding.
(ii) Diamond
has a high melting point.
(iii) Graphite
is a good conductor of electricity.
31.
(a) The structural
formula of an ester is CH3COOC2H5 Write the
structural formulae of the corresponding alcohol and the acid.
(b)
(i) Mention the experimental conditions involved in obtaining ethane from
ethanol.
(ii)
Write the chemical equation for the above reaction.
(c)
Explain the cleansing action of soap.
32.
Cough syrups, pudin
hara and tonics contain alcohol. Some people are habitual of drinking alcohol.
Instead of drinking alcohol, they have started using cough syrups which contain
alcohol and cause addiction. To solve this problem, government is thinking to
ban cough syrups.
(a) What
is an alcohol?
(b) Should
production of cough syrups be banned? Give three reasons to support your
answer.
(c) As
a student ‘what initiative would you take to make people aware of harmful
effects of taking cough syrups unnecessarily? Give two suggestions.
33.
Petrol and diesel are
in great demand as vehicles are increasing day-by-day. Our natural resources
are limited. A major amount of foreign currency is spent on import of
petro-products, that is why prices are increasing day-by-day. Air pollution is
increasing day-by-day. CNG can solve problem to some extent. Car-pooling can
also help i.e., people going to same
destination can go together and share expenses of fuel. Ethanol can be mixed
with petrol to reduce pollution. Use of bicycles can be increased. Hybrid cars,
electric cars can also help. Use of public transport and metro is very useful.
(a) How
do we get petro-products?
(b) How
will you make people aware that petro-products should be used judiciously? Give
two suggestions.
(c) What
value is involved in car-pooling?
(d) How
can we reduce air pollution? Give two ways.
34.
A prestigious school of Delhi has large
canteen which sells burgers, patties, cold drinks, pizzas, samosas, chips etc.
most of the children enjoy eating these junk food. School authorities have
asked them to sell fresh fruit juices, sprouts, boiled corns, fresh fruits,
nimbu pani, etc. but sale of these items is very less. Some children take sips
from same cold drink bottle and bites of same burger.
(a) Which
preservative is present in cold drinks?
(b) Which
acid is present in vinegar added to vegetable chowmein?
(c) What
will you do to make people aware that junk food is harmful for helath? Give two
suggestions.
(d) What
is wrong/right in sipping cold drink from same bottle or biting same burger by
many students? Give reason.
(e) Do
you think junk food and cold drink should be banned in school canteen as per the
directive of Hon’ble High Court’s order? Give two reasons in support of your
answer.
CHAPTER – 2
1.
How many vertical columns are there in the
modern periodic table and what are they called?
2.
Write two reasons responsible for late
discovery of noble gases.
3.
The atomic numbers of three elements X, Y and
Z are 3, 11 and 17 respectively. State giving reason which two elements will
show similar chemical properties.
4.
Give the number of elements in 2nd and 5th
period in Modern Periodic, table.
5.
A metal M belongs to 13th group in the modern
periodic table. Write the valency of the metal.
6.
Why was the system of classification of
elements into triads not found suitable?
7.
Did Dobereiner’s triads also exist
in the columns of Newlands’ Octaves?
8.
What were the limitations of
Newlands’ Law of Octaves?
9.
and 
isotopes of chlorine, would you place them in
different slots because their atomic masses are different? Or would you place
them in the same position because their chemical properties are the same?
and isotopes of chlorine, would you place them in
different slots because their atomic masses are different? Or would you place
them in the same position because their chemical properties are the same?
10.
What were the criteria used by
Mendeleev in creating the periodic table?
11.
An element ‘X’ has atomic number
13.
(a) Write
its electronic configuration.
(b) State
the group to which ‘X’ belongs.
(c) Is
‘X’ a metal or a non-metal?
(d) Write
the formula of its bromide.
12.
An element ‘M’ has atomic number 11.
(a) Write
its electronic configuration.
(b) State
the group to which ‘M’ belongs.
(c) Is
‘M’ a metal or a non-metal?
(d) Write
the formula of its chloride.
13.
How can the valency of an element be
determined if its electronic configuration is known? What will be the valency
of an element of atomic number 9 (nine)?
14.
Choose from the following: 20Ca, 3Li,
11Na, 10Ne
(a) An
element having two shells completely filled with electrons.
(b) Two
elements belonging to the same group of the periodic table.
15.
An element ‘E’ has following electronic
configuration:
|
K
|
L
|
M
|
|
2
|
8
|
6
|
16.
An element has atomic number 13.
(a) What
is the group and period number to which this element belongs?
(b) Is
this element a metal or a non-metal? Justify your answer.
17.
How does the electronic configuration of an
atom of an element relate to its position in the modern periodic table? Explain
with one example.
18.
In the modern periodic table, the element
Calcium (atomic number = 20) is surrounded by elements with atomic numbers 12,
19, 21 and 38. Which of these elements has physical and chemical properties
resembling those of Calcium and why?
19.
State two main properties of
elements on which Mendeleev’s periodic classification was based. Why could no
fixed position be assigned to hydrogen in his periodic table?
20.
The elements of the third period of the
periodic Table are given below:
|
Group
 |
I
|
II
|
III
|
IV
|
V
|
VI
|
VII
|
|
Period 3
 |
Na
|
Mg
|
Al
|
Si
|
P
|
S
|
Cl
|
21.
An element X (atomic number 17) reacts with an
element Y (atomic number20) to form a compound.
(a) Write
the position of these elements in the modern periodic table.
(b) Write
the formula of the compound formed.
Justify
your answer in each case.
22.
The atomic number of an element ‘X’ is 20.
Write
(a) Its
valency,
(b) Whether
it is a metal or non-metal,
(c) The
formula of compound formed when the element ‘X’ reacts with an element ‘Y’ of
atomic number 8.
Justify
your answer in each case.
23.
Two elements X and Y belong to group 1 and 2
respectively in the same period of periodic table. Compare them with respect
to:
(i)
The number of valence electrons in their
atoms
(ii) Their
valencies
(iii) Metallic
character
(iv) The
sizes of their atoms
(v) The
formulae of their oxides
(vi) The
formulae of their chlorides
24.
The positions of three elements A, B and C in
the periodic table are indicated below:
|
Group 16
|
Group 17
|
|
|
―
|
―
|
(First Period)
|
|
―
|
A
|
(Second
Period)
|
|
―
|
―
|
(Third Period)
|
|
B
|
C
|
(Fourth
Period)
|
25.
(a) What is meant by periodicity in
properties of elements with reference to the periodic table?
(b) Why
do all the elements of the same group have similar properties?
(c) How
will the tendency to gain electrons change as we go from left to right across a
period? Why?
26.
(a) What are ‘groups’ and ‘periods’
in the ‘periodic table’?
(b) Two
elements M and N belong to group I and II respectively and are in the same
period of the periodic table. How do the following properties of M and N vary?
(i)
Sizes of their atoms
(ii) Their
metallic characters
(iii) Their
valencies in forming oxides
(iv) Molecular
formulae of their chlorides
27.
The position of three elements A, B and C in
the periodic Table are shown below:
|
Group 16
|
Group 17
|
|
―
|
―
|
|
―
|
A
|
|
―
|
―
|
|
B
|
C
|
Giving
reasons, explain the following:
(a) Element
A is a non-metal
(b) Element
B has a larger atomic size than element C.
(c) Element
C has a valency of 1.
CHAPTER – 3
1.
Why is DNA copying necessary during reproduction?
2.
Name any two types of asexual
reproduction.
3.
State the method used for growing rose plants.
4.
Write the expanded form of AIDS.
5.
List two functions performed by ovaries in a
human female.
6.
What is the function of pollen
grains in flowers?
7.
What is the difference between
binary and multiple fission?
8.
How does hydra reproduce? Name
another organism that reproduces by the similar method.
9.
Which group of plants shows double
fertilization?
10.
What is the main difference between stem
cutting and layering?
11.
What is the age of puberty in human females?
12.
“The chromosome number of the
sexually reproducing parents and their offspring is the same”. Justify this
statement.
13.
How does growing embryo get nutrition from the
mother’s blood?
14.
Define the term puberty. List two
changes observed in girls at the time of puberty.
15.
Write any two differences between
binary fission and multiple fission in a tabular form as observed in cells of
organisms.
16.
Explain giving one example of each, the
unisexual and the bisexual flowers.
17.
What is regeneration? State a reason why a
more complex organism cannot give rise to new individuals through this method.
18.
What is ‘reproduction’? Mention the importance
of DNA copying in reproduction.
19.
Name any two sexually transmitted diseases.
What advice is given to prevent them?
20.
(a) list two sexually transmitted
diseases in each of the following cases:
(i)
Bacterial infections
(ii)
Viral infections
(b) How may the spread
of such diseases be prevented?
21.
Explain the meaning of sexually transmitted
diseases (STDs). Give two examples each, caused due to (i) bacterial infection
and (ii) viral infection. State in brief how the spread of such diseases may be
prevented.
22.
Illustrate the following with the help of
suitable diagrams:
(i)
Binary Fission in Amoeba
(ii)
Leaf of Bryophyllum with buds.
23.
What does HIV stand for? Is AIDS an infectious
disease? List any four modes of spreading AIDS.
24.
Differentiate between ‘self-pollination’ and
‘cross-pollination’. Describe ‘double fertilization, in plants.
25.
(a) Why does fertilization occur
only once in a month in a human female? Explain.
(b)
Prenatal sex determination has been prohibited by law. State the necessity of
enforcement of this law.
(c)
Where are human testes located and why? State their functions.
26.
Describe in brief the role of (i) testis (ii)
seminal vesicle, (iii) vas deferens, (iv) ureter and (v) prostate gland in
human male reproductive system.
27.
Draw a diagram of a human female reproductive
system and label the part
(i)
That produces egg
(ii)
Where fusion of egg and sperm take place
(iii)
Where zygote is implanted
What happens to human
egg when it is not fertilized?
28.
(a) What is spore formation?
(b)
Draw a diagram showing spore formation in Rhizopus.
(c)
List two advantages for organisms to reproduce themselves through spores.
29.
Distinguish between a gamete and zygote.
Explain their roles in sexual reproduction.
30.
What is placenta? Mention its role during
pregnancy?
31.
How are general growth and sexual maturation
different from each other?
32.
Why are budding, fragmentation and
regeneration all considered as asexual types of reproduction?
CHAPTER – 4
1.
Name the genetic material that is responsible
for inheritance of traits.
2.
What is a gene?
3.
Lost the main concepts in Darwin’s theory of
Natural Selection.
4.
Name the plant on which Mendel
performed his experiments.
5.
Give an example of homologous organ
from the plant kingdom.
6.
Why can the wings of a bird and the wings of a
bat not to be considered homologous?
7.
What will be the sex of a child who
inherits X chromosome from his/her father?
8.
A Mendelian experiment consists in
breeding tall pea plants bearing violent flowers with short pea plants bearing
white flowers. The progeny all bore violet flowers but almost half of them are
short. This suggests that the genetic make-up of the tall parent can be
depicted as – (a) TTWW (b) TTww (c) TtWW (d) TtWw
9.
An example of homologous organs is
(a) Our
arm and a dog’s forleg
(b) Or
teeth and an elephant’s tusks
(c) Potato
and runners of grass
(d) All
of the above.
10.
Why is variation beneficial for the
species, but not necessarily for the individual?
11.
Explain the mechanism of sex
determination in humans.
12.
A blue colour flower plant denoted
by BB is crossed with a white colour flower plant denoted by ww.
(a) State
the color of the flower we would expect in their F1 progeny.
(b) Write
the percentage of plants bearing white flower selfed.
(c) State
the expected ratio of the genotype BB and Bw in the F2 progeny.
13.
If we cross pure-bred tall
(dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea
plants of F1 generation. If we now self-cross the pea plant of F1
generation, then we obtain pea plants of F2 generation.
(a) What
do the plants of F1 generation look like?
(b) State
the ratio of tall plants to dwarf plants in F2 generation.
(c) State
the type of plants not found in F1 generation but appeared in F2
generation, mentioning the reason for the same.
14.
Distinguish between homologous
organs and analogous organs. In which category would you place wings of a bird
and wings of a bat? Justify your answer giving a suitable reason.
15.
Define the term ‘evolution’.
“Evolution cannot be equated with progress”. Justify this statement.
16.
How are fossils formed? Describe,
in brief two methods of determining the age of fossils.
17.
Define ‘evolution’. Describe Darwin’s
theory of evolution.
18.
How do Mendel’s experiment show
that traits may be dominant or recessive?
19.
How do Mendel’s experiments show
that traits are inherited independently?
20.
Satyam is a ten-years old boy in
perfect health. However a recent genetic test has revealed that he has a gene
which makes him vulnerable to a heart disease. He does not take regular
medicine to protect himself from the heart disease. The insurance company who
has been doing Satyam’s medical insurance for last nine years has now denied to
renew his health insurance. The insurance company argues that since the gene is
present from birth which is pre-existing medical condition, Satyam’s insurance
cannot be renewed.
(a) Is
it correct for the insurance company to deny medical insurance to Satyam?
Support your answer with proper reasons.
(b) Should
genetic tests be banned?
(c) What
steps can the government take to stop such situations in future?
21.
While playing near a sugarcane
field, Mohan noticed that the plants are almost similar to one another. At the
same time, he noticed the mango trees in the next plot of land which are not
similar to one another. Mohan’s brother told Mohan that sugarcane reproduces
sexually, hence there is little variation, Mango reproduces sexually, hence
there is larger variation.
(a) Why
sugarcane cannot reproduce sexually?
(b) Can
mango reproduce asexually?
(c) If
a person wants to have a flower garden, what type of plants should he grow?
CHAPTER – 5
1.
Explain why a ray of light passing
through the centre of curvature of a concave mirror, gets reflected along the
same path.
2.
What is the nature of the image
formed by a concave mirror if the magnification produced by the mirror is +3?
3.
Between which two points of a
concave mirror should an object be placed to obtain a magnification of -3?
4.
“The refractive index of carbon
disulphide is 1.63.” what is the meaning of this statement in relation to speed
of light?
5.
Between which two points related to
a concave mirror should an object be placed to obtain on a screen an image
twice the size of the object?
6.
The refractive indices of four
media A, B, C and D are given in the following table:
|
Medium
|
A
|
B
|
C
|
D
|
|
Refractive Index
|
1.33
|
1.50
|
1.52
|
2.40
|
7.
“The refractive index of diamond is
2.42”. What is the meaning of this statement in relation to speed of light?
8.
Draw the following diagram in your
answer book and show the formation of image of the object AB with the help of
suitable rays.
9.
Define 1 dioptre of power of a
lens.
10.
The magnification produced by a
plane mirror is + 1. What does this mean?
11.
“A concave mirror of focal length ‘f’ can form a magnified, erect as well
as an inverted image of an object placed in from t of it.” Justify this
statement stating the position of the object with respect to the mirror in each
case for obtaining these images.
12.
State the two laws of reflection of
light.
13.
Distinguish between a real and a
virtual image of an object. What type of image is formed (i) by a plane mirror,
(ii) on a cinema screen?
14.
What is the minimum number of rays
required for locating the image formed by a concave mirror for an object? Draw
a ray diagram to show the formation of a virtual image by a concave mirror
15.
Explain with the help of a diagram,
why a pencil partly immersed in water appears to be bent at the water surface.
16.
Draw ray diagrams to represent the
nature, position and relative size of the image formed by a convex lens for the
object placed:
(a) At
2F1.
(b) Between
F1 and the optical centre O of lens.
17.
An object is placed at a distance
of 12 cm in front of a concave mirror. It forms a real image four times larger
than the object. Calculate the distance of the image from the mirror.
18.
What is the meaning of (i) optical
centre and (ii) principal focus of a convex lens?
19.
You are given kerosene, turpentine
and water. In which of these does the light travel fastest? Given refractive
indices of kerosene, turpentine and water are 1.44, 1.47 and 1.33 respectively.
20.
Find the focal length of a lens of
power -2.0 D. what type of lens is this?
21.
State the type of mirror preferred
as (i) rear view mirror in vehicles, (ii) shaving mirror. Justify your answer
giving two reasons in each case.
22.
Name the type of mirror used in the
following situations:
(i)
Headlights of a car
(ii) Rear-view
mirror of vehicles
(iii) Solar
furnace
Support your answer with reason.
23.
Draw a ray diagram and also state
the position, the relative size and the nature of image formed by a concave
mirror when the object is placed at the centre of curvature of the mirror.
24.
Define, ‘refractive index of a
transparent medium.’ What is its unit? Which has a higher refractive index, glass
or water?
25.
(a) “The refractive index of
diamond is 2.42”. What is the meaning of this statement?
(b) Name
a liquid whose mass density is less than that of water but it is optically
denser than water.
26.
An object is placed between
infinity and the pole of a convex mirror. Draw a ray diagram and also state the
position, the relative size and the nature of the image formed.
27.
For which position of the object
does a convex lens form a virtual and erect image? Explain with the help of a
ray diagram.
28.
A concave lens has focal length of
20cm. At what distance from the lens a 5cm tall object be placed so that it
forms an image at 15cm from the lens? Also calculate the size of the image
formed.
29.
A 5.0 cm tall object is placed
perpendicular to the principal axis of a convex lens of focal length 20 cm. The
distance of the object from the lens is 30 cm. By calculation determine (i) the
position and (ii) the size of the image formed.
30.
(a) If the image formed by a lens
is diminished in size and erect, for all positions of the object, what type of
lens is it?
(b) Name the point on the lens
through which a ray of light passes undeviated.
(c) An object is placed
perpendicular to the principal axis of a convex lens of focal length 20cm. The
distance of the object from the lens is 30cm. Find (i) the position (ii) the
magnification and (iii) the nature of the image formed.
31.
(a) What is meant by ‘power of a
lens’?
(b) State and define the S.I. unit
of power of a lens.
(c) A convex lens of focal length
25cm and a concave lens of focal length 10cm are placed in close contact with
each other. Calculate the lens power of this combination.
32.
(a) Draw a ray diagram to show the
formation of image of an object placed between infinity and the optical centre
of a concave lens.
(b) A concave lens of focal length
15cm forms an image 10cm from the lens. Calculate
(i) the distance of the object from
the lens
(ii) the magnification for the
image formed
(iii) the nature of the image
formed
33.
Draw the ray diagram in each case
to show the position and nature of the image formed when the object is placed:
(i)
At the centre of curvature of a concave
mirror
(ii)
Between the pole P and focus F of a
concave mirror
(iii)
In front of a convex mirror
(iv)
At 2F of a convex lens
(v)
In front of a concave lens
34.
Why does a light ray incident on a rectangular
glass slab immersed in any medium emerges parallel to itself? Explain using a
diagram.
35.
Draw a ray diagram showing the path
of rays of light when it enters with oblique incidence (i) from air into water;
(ii) from water into air.
36.
Long long ago, there lived in a
village, a man named Kanta Prasad. He alone was a trouble maker. A sadhu by the
name Markandey also lived in this village. One day Kanta said to Markandey
“Just a month back, I had a dream in which you asked me for a loan of Rs. 20,
000/-”. He demanded to return him back. The perplexed Markandey took his
problem to the village panchayat. The panchayat leader said, “Bring a large
mirror and place it in front of this court.” The panchayat leader then placed
twenty thousand rupees in front of the mirror. The panchayat leader then asked
to the Kanta Prasad stood ashamed.
Markandey
was relieved. All the villagers were astonished for the wise judgement of their
panchayat leader.
(a) Which
physical phenomenon is used by panchayat leader?
(b) State
the two properties of mirror in the given case.
(c) What
can you say about the quality shown by panchayat leader?
37.
Three students were on the way from
Pune to Mumbai. Gopal, the one of the student among them who was driving the
car saw from his side mirror that the car which was behind their car had met
with an accident. He suddenly applied brakes even after his friends asked him
to leave the situation as it was. But gopal didn’t agree and got down of car
and was also able to persuade his friends to help the injured. The three
students took the injured person to the nearest hospital. After getting
consciousness, the victims please them with thanks for saving their life.
(a) Name
the type of mirror from which Gopal saw the accident.
(b) Why
this mirror is used as a side mirror in the vehicle? Show it with the help of
ray diagram.
(c) What
can you learn from the Gopal’s character?
CHAPTER – 6
1.
What will be the colour of the sky,
when it is observed from a place in the absence of any atmosphere? Why?
2.
The sky appears dark instead of
blue to an astronaut. State its reason.
3.
State on function of iris in human
eye.
4.
State one function of pupil in
human eye.
5.
What is Tyndall effect?
6.
Name the type of particles which
acts as a prism in the formation of rainbow in the sky.
7.
Why is red colour selected for
danger signal lights?
8.
What kind of lens is used in the
spectacles of a person suffering from myopia (near-sightedness)?
9.
A star sometimes appears brighter
and some other times fainter. What is this effect called? State the reason for
this effect.
10.
What is the colour of the clear sky
during day time? Give reason for it.
11.
Draw a ray diagram to show the
formation of a rainbow and mark the point where (i) dispersion, (ii) internal
reflection occurs.
12.
“the time difference between the
actual sunset and the apparent sunset is about 2 minutes.” What is the reason
for the same? Explain with the help of a diagram.
13.
Explain why do the planets not
twinkle but the stars twinkle.
14.
Draw a ray diagram to show the
refraction of light through a glass prism.
Mark on it (a) the incident ray,
(b) the emergent ray and (c) the angle of deviation.
15.
What is a spectrum? Why do
different coloured rays deviate differently on passing through a glass prism?
16.
When and where do we see a rainbow?
How is a rainbow formed? Draw a labeled diagram to illustrate the formation of
rainbow.
17.
What eye defect is hypermetropia?
Describe with a ray diagram how this defect of vision can be corrected by using
an appropriate lens.
18.
Name the three common defects of
vision. What are their causes? Name the type of lens used to correct each of
them.
19.
Explain why?
(a) Myopic
person prefer to remove his spectacles while reading a book.
(b) A
hypermetropic person prefer to remove the spectacles while looking at the sky.
20.
Explain the role played by (i)
ciliary muscles, (ii) aqueous humour.
21.
Four friends went to a picnic. The
weather was pleasant. They played various games and then had snacks. Suddenly,
Shyam, one of them, noticed seven colours in the sky. He said to others, “Wow,
what a rainbow!” Then Ram, one of them, asked him “What is Rainbow”? He then
explained to all about its formation. After that everyone in the group thanked
him for the knowledge, he had given to them.
(a) If
you were in the place of Shyam, how you would have explained such a natural
phenomenon?
(b) Which
device can be used to obtain such a phenomenon?
(c) If
Shyam was facing the rainbow, then where was the Sun?
(d) What
is the moral value which is shown by Shyam?
22.
‘Sania and Shreya’ are best friends
and study in grade 4. Recently, Sania has been facing difficulty in reading the
blackboard text from the last desk. Shreya is little uncomfortable and wonders
why sania avoids sitting on the last desk. On observation she found that sania
often carries junk food in her lunch. Shreya has started sharing her lunch-full
of green vegetables and fruits with her. Sania is now better and has also
started taking a ‘balanced diet’.
(a) Name
the eye defect Sania is suffering from.
(b) What
are the two possible deformities related to her eye defect?
(c) What
value is shown by Shreya and Sania?
CHAPTER – 7
1.
Why should biodegradable and non
biodegradable wastes be discarded in two separate dust bins?
2.
List two components of an
ecosystem.
3.
Bacteria and fungi are called
decomposers. Why?
4.
Name two decomposers operating in
our ecosystem.
5.
Why did United Nations act to
control the production of chlorofluorocarbons (CFCs) used in refrigeration’s?
6.
Distinguish between biodegradable
and non-biodegradable wastes.
7.
Why are green plants called
‘producers’?
8.
What is meant by the term
‘Environment’?
9.
Construct an aquatic food chain
showing four trophic levels.
10.
What are biodegradable and
non-biodegradable substances? Select two biodegradable pollutants from the
following:
Agricultural
waste, glass, plastic, sewage, DDT.
11.
Why are bacteria and fungi called
decomposers? List any two advantages of decomposers to the environment.
12.
(a) What is ‘environmental
pollution’?
(b) Distinguish between
biodegradable and non-biodegradable pollutants.
(c) Choose the biodegradable
pollutants from the list given below:
Sewage, DDT, radioactive waste,
agricultural waste.
13.
What are chlorofluorocarbon? How
are they responsible for causing ozone hole in atmosphere? What will be the
consequences of ozone hole?
CHAPTER – 8
1.
Name any two items which can be
easily recycled but generally thrown in the dustbins by us?
2.
List any two industries based on
forest produce.
3.
What are the two kinds of natural
resources?
4.
Define the term ‘Conservation of
environment’.
5.
Why is sustainable management of
natural resources necessary? Which one out of reuse and recycle would you suggest
to practice and why?
6.
Write the harmful effects of using
plastic bags on the environment. Suggest alternatives to plastic bags.
7.
What is water harvesting? Mention
any two water harvesting structures.
8.
List any four advantages of water
harvesting.
9.
“Burning fossil fuels is a cause of
global warming”. Justify this statement.
10.
List any four characteristics of a
good fuel.
11.
What are non-renewable resources of
energy? Give two examples of such resources.
12.
Suggest any four changes that you
would like to incorporate in the life-style of students of your age to move
towards a sustainable use of available resources.
13.
Suggest any two ways to strike a
balance between environment and development.
14.
What is a dam? Write two main
advantages and two ill-effects of constructing a big dam.
15.
Suggest three ways to maintain a
balance between environment and development to survive.
16.
Describe any three ways in which
water is important for the activities of living beings.
Answers of these questions plzz
ReplyDeleteAnswers of these questions plzz
ReplyDeleteCould you provide the answer to this question?
ReplyDeleteWhile playing near a sugarcane field Mohan noticed that the plants are almost similar to one another . At the same time he noticed the mango trees in the next plot of land are not similar to one another. Mohans brother told Mohan that sugarcane reproduces asexually hence there is larger variation.
a) Why cant sugarcane reproduce sexually?
b) Can mango reproduce sexually?
c) If a person wants to have a flower garden what type of plants should he keep?