-
How the gases can be liquefied?
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Where do the lipids and proteins constituting
the cell membrane get synthesized?
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A person applies some force on an almirah
but it does not move, why?
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Why is the cover slip gently pressed down?
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What type of solution is formed when a well
stirred and filtered solution of egg albumin is mixed with water?
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A student measured the minimum force
F1 to just move a rectangular wooden block with largest surface area
on a surfaceby a spring balance. Again measured the minimum force F2
to just move the block kept with smallest surface area on the table. After
repeating his experiment, he established a relation between the two forces. Find
this relation.
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Write the condition, at which reaction
of iron and sulphur takes place to form iron sulphide?
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Which solvent is used to
separate sulphur from iron filings?
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In the given figure, find the
value of zero error and least count.
-
What is the behavior of MgO in
the presence of water?
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When you heat a magnesium ribbon
ona burner, it burns with a blinding white light and some residue is left after
burning. What is this residue?
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Four test tubes P, Q, R, S shown
below contain the following:
On adding 2 drops of iodine to
each test tube, which will show blue-black solution?
-
(a) Write the correct sequence
of steps taken for separating a mixture of ammonium chloride, sand and common
salt.
(b) In the reaction,
which one will turn blue litmus
red?
-
Why plant cell contain large
size vacoule, as compared to animal cell?
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Look at the diagram above and
answer the following questions
(a) When a force is applied
through thefree end of the spring balance A, thereading on the spring balance A
is15 g wt. What will be the reading of spring balance B?
(b) Write reasons for your
answer.
(c) Name the force which balance
Aexerts on balance B and the force of balance B on balance A.
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(a) To prepare iron sulphide, by
heating a mixture of iron fillings and sulphur powder, which apparatus should
be use?
(b) What happens when magnet is
rolledin the compound of iron sulphide?
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The teacher asked the students to record
correctly results of the experiment done to detect the presence of metanil
yellow in the adulterated arhar dal sample that was provided to them.
|
|
Procedure
|
Observation
|
Inference
|
|
A
|
5 g dal + 5
g metanil yellow.
|
Dal turns
yellow.
|
Metanil yellow present.
|
|
B
|
5 g dal + 5
ml water + 2 drops of HCI.
|
Solution turns pink.
|
Metanil yellow present in the sample.
|
|
C
|
5 g dal + 5
ml water + pinch of metanil yellow.
|
Water turns yellow.
|
Metanil yellow present.
|
|
D
|
5 g dal + 5
ml water + 2 drops of HCI.
|
Metanil yellow present.
|
Water turns yellow and then pink.
|
Which is the correct recording of the
experiment? justify your answer.
-
Give any two differences between
macronutrients and micronutrients.
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Write two infectious diseases
each of cow, poultry and fishes.
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Alka's mother bought a new refrigerator
which was frost free. Alka was unaware of the frost free technology of
refrigerator. She wanted to know about this. So, she asked to her mother about
this.
(a) What are the values shown by
Alka?
(b) How did her mother explain
suchthing?
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Show that the state of matter
can be changed into another state by changing the temperature. How can you show
the inter conversion of the states of matter?
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Calculate the mass of sodium
sulphate required to prepare its 20% (mass percent) solution in 100 g of water?
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What is the difference between
the plasma membrane and cell wall? Give the functions of each one.
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Answer the following questions
(a) What is division of labour
with reference to multicellular organisms?
(b) Why striated muscles are
also knownas skeletal muscles?
(c) Which structure takes
impulse a way from a neuron.
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Answer the following questions
(a) Heart pumps blood all
through the body. Can you explain the reason behind this peculiar ability of
heart?
(b) Animals of colder regions
and fishesof cold water have thicker layer of subcutaneous fat. Why?
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An object covers a distance S1,
with a constant speed v1 and then covers a further distance s2
with a constant speed v2. Find an expression for his average speed.
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A girl of mass 40 kg jumps with
a horizontal velocity of
onto
a stationary cart with friction less wheels. The mass of the cart is 3 kg. What
is her velocity as the cart starts moving? Assume that there is no external unbalanced
force working in the horizontal direction?
-
A 30 kg shell is flying at
suddenly
it explodes and one of its partof 18 kg comes to rest while the remaining part
flies off. Find the velocity of the latter.
-
Planet Mars has radius one-half
of the Earth and mass 1/9th of the Earth. Findthe value of g on the surface of
Mars. Given that value of g on the surface of Earth is
-
A car falls off a ledge and
drops to the ground in 1 s. Let
(for
simplifying the calculation).
(a) What is its speed on
striking theground?
(b) How high is the ledge from
theground?
(c) What is its average speed
during the 1 s?
-
Humans and all other animals
dependon plants for their food. Hard work of several years have resulted in the
development of tissue culture technology by scientists. What can be the
application of such technology inour present society?
Or
Name the following
(a) Tissue that forms the inner
lining of our mouth.
(b) Tissue that connects muscle
to bonein humans.
(c) Tissue that transport food
in plants.
(d) Tissue that stores fat in
our body.
(e) Connective tissue with a
fluid matrix.
(f) Tissue present in the brain.
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Answer the following questions
(a) Farmer 'X' planted soyabean
+ maize+ cowpea (lobia) in the same field simultaneously in a set row pattern. Farmer
'Y' planted cereal crop in one season and leguminous plant in next season on
the same piece of land inpreplanned succession. Name the cropping pattern used
by the farmers'X' and 'Y'.
(b) What are the advantages of
different cropping patterns followed by the farmers 'X' and 'Y'?
(c) Differentiate between mixed cropping
and mixed farming.
Or
One of your family friend is
thinking toopen a dairy farm for economic purpose. He wants to earn profits by selling
milk. While he was discussing this with your father, what additional information
can you give based on your knowledge for maintenance of catties?
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A 8000 kg engine pulls a train
of 5 wagons, each of 2000 'kg, along ahorizontal track. If the engine exerts a force
of 40000 N and the track offers a friction force of 5000 N, then calculate
(a) the net acceleration force,
(b) the acceleration of the
train and
(c) the force of wagon 1 on
wagon 2.
Or
The driver of train A travelling
at a speed of
applies
brakes and retards the train uniformly. The train stops in 5 s. Another train B
is travelling on the parallel with a speed of
Its
driver applies the brakes and the train retards uniformly; train B stops in 10
s. Plot speed-time graphs for both the trains on the same axis. Which of the
trains travelled farther after the brakes were applied?
-
Give reasons
(a) A gas fills completely the
vessel in which it is kept.
(b) A gas exerts pressure on the
walls of the container.
(c) A wooden table should be
called asolid.
(d) We can easily move our hand
in air, but to do the same through a solid block of wood, we need a karate expert.
Or
(a) You want to wear your favorite
shirtto a party, but the problem is that it isstill wet after a wash. What
steps would you take to dry it faster?
(b) It is a hot summer day, Priyanshi
and Ali are wearing cotton and nylonclothes respectively. Who do you think
would be more comfortable and why?
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Explain the following giving
examples
(a) Saturated solution (b)
Pure substance
(c) Colloid (d)
Suspension
Or
A group of students took an old
shoe box and covered it with a black paper from all sides. They fixed a source
of light (a torch) at one end of the box by making a hole in it and made
another hole on the other side to view the light.
They placed a milk sample
containedin a beaker/tumbler in the box as shown in the figure. They were
amazed to see that milk taken in the tumbler was illuminated. They tried the
sameactivity by taking a salt solution but found that light simply passed
throughit?
(a) Explain why the milk sample
was illuminated. Name the phenomenon involved.
(b) Same results were not
observed witha salt solution. Explain.
(c) Can you suggest two more
solutions which would show the same effect as shown by the milk solution?
-
Derive the equations of motion
for uniformly accelerated motion from velocity-time graph.
Or
Distance travelled by a train
and time taken by it is shown in the following table.
(a) Plot distance-time graph.
(b) What is the average speed of
the train?
(c) When is the train travelling
at the highest speed?
(d) At what distance does the
train slowdown?
(e) Calculate the speed of the
train between 10:40 AM to 11:00 AM.
|
Time
|
Distance (in km)
|
|
10:00 am
|
0
|
|
10:30 am
|
25
|
|
10:40 am
|
28
|
|
11:00 am
|
40
|
|
11:15 am
|
42
|
|
11:30 am
|
50
|
