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A student draws the following sketch of
stomatal apparatus and numbers theparts to label them. Identify the number by
which chloroplast is denoted.
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In the experiment, to show that
light is necessary for photosynthesis, a potted plant is first kept in dark for
a day. Give reason.
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To show that CO2 is
given out during respiration in seeds, which substance one uses?
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What products are formed during
respiration in our muscles when there is lesssupply of oxygen?
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If there are 10 divisions in a
voltmeter between 5 V and 6V mark, then find the least count.
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What does the slope of following
graph calculate?
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In which form, zinc metal is
used for experimental purposes?
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What is the colour of residue
obtained on heating FeSO4 crystals?
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In the following metals, what is
the correct order of the metals in increasing order of reactivity?
Al, Fe, Zn
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Name the physical quantity whose
unitis Volt/Ampere.
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Give one advantage and one
limitation of solar cell.
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Name the most reactive and the
least reactive metal.
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On what factors the resistance
of wire depends?
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Zinc granules were added to zinc
sulphate, copper sulphate, aluminium sulphate and iron sulphate solution as shown
below.
Find the two beakers in which
you would observe the deposition of metalon zinc?
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Four students. were asked by
theirteacher to arrange the set ups I-IV asgiven below and identify the
gasevolved in each case, if any.
After observations, they arrived at the following
inferences and recorded these in the form of a table given below.
Student
|
I
|
II
|
III
|
IV
|
A
|
Hydrogen
|
No gas
|
Carbon dioxide
|
Hydrogen
|
B
|
Carbon dioxide
|
Hydrogen
|
No gas
|
Carbon dioxide
|
C
|
Carbon dioxide
|
Hydrogen
|
Hydrogen
|
No gas
|
D
|
No gas
|
Carbon dioxide
|
Carbon dioxide
|
Hydrogen
|
Which student has given the correct observation
and inferences? Give chemical reactions also.
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Write the technical terms for
following events.
(a) The movement of plant in
thedirection of light.
(b) The movement of plant parts
inresponse to water.
(c) The movement of plant parts
towards chemical substance.
(d) The downward movement of
roots in response to gravitational force.
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What are the differences between
the manner in which movement takes place in a sensitive plant and the movement
in our legs?
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(a) How hemoglobin level is
expressedin human beings?
(b) Which disease is caused due
to lackof hemoglobin?
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When sodium iodide is added
tolead nitrate, a precipitate is formed. Write an equation for it. What is the
colour of precipitate? Name the type of reaction.
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Copper powder is heated over
aburner in a China dish. Write your observations and chemical reaction
involved. How can you get reactant back?
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Distinguish between strong acid and
weak acid with examples.
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What is aqua regia? How is it obtained?
State its properties.
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Draw symbols for (a) battery of 3
cells (b) bulb (c) rheostat (d) closed key. Use these components to make a
simple circuit.
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What is a solenoid? Draw
fieldlines around a current carrying solenoid.
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(a) What are the energy
conversions in a wind energy farm?
(b) What condition is necessary
forwind farm to produce energy?
(c) Why are wind farm expensive
tomaintain?
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What are the consequences of
over secretion and under secretion of growth hormone? How is timing and amount
of a hormone released regulated?
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Compare the power used in
resistor
in each of following circuits.
(a) A 6 V battery in series with
and
resistors
(b) A 4 V battery in parallel
with
and
resistors
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(a) List three methods of
producing magnetic fields.
(b) What is the magnetic field
insidea long straight solenoid carrying current?
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Name the enzymes present in
pancreatic juice and give their functions.
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Hydrogen is not a metal but it
has been assigned a place in the reactivity series of metals. Explain.
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What happens to food inside
small intestine? How do intestinal walls facilitate food absorption?
Or
Shanu told his father that plant
exude out alot of water in vapour form from leaves, define it. What is its
importance? How do stomata help in this process?
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Find equivalent resistance and total
currentin the following.
Or
(a) For the circuit shown in the
given figure,
What is the value of
(i) current through
resistor?
(ii) potential difference across
resistor?
(b) In an electrical circuit,
three incandescent bulbs A, B and C of rating 40 W 60 W and 100 W respectively
are connected inparallel to an electric source. Write the order of brightness.
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The electric bell of Mr.
Sharma's house is not working. He asks his son to get it changed.His son first
checks for the fault. The gong is found displaced, he repairs it to work again.
(a) Sketch the values of Mr.
Sharma.
(b) Which values of his son are appreciable?
(c) On which principle is
electric bellbased? Explain that principle andgive one more practical
applicationof it.
Or
Sakshi's bus arrives at 7:40 am.
Shereaches the stop at 7:35 am and waits. Sohan does not reach at even 7:45 am Sakshi
goes up to driver and asks himto close the engine, who ignores it.
(a) Appreciate the values of
Sakshi.
(b) What values must be
illustrated in Sohan and driver?
(c) Why does Sakshi ask the
driver toclose the engine?
(d) Burning of fuel is chemical
change orphysical change.
(e) The fuel used in the bus is
renewableor non-renewable.
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(a) For making cake, baking
powder istaken. If at home your mother uses baking soda instead of baking powder
in cake.
(i) How will it affect the taste
of the cake and why?
(ii) How can baking soda be
converted into baking powder?
(iii) What is the role of
tartaric acid added to baking soda?
(b) Name the acid present in ant
sting and give its chemical formula. Also give the common method to get relief
from the discomfort caused by the ant sting.
Or
(a) A metal carbonate X on
reacting with an acid gives a gas which when passed through a solution Y gives
the carbonate back. On the other hand, a gas G that is obtained at anode
during electrolysis of brine is
passed on dry Y, it gives a compound Z, used for disinfecting drinking water.
Identify X, Y, G and Z.
(b) What happens when nitric
acid is added to egg shell?
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Describe an activity to
demonstrate reaction of steam on iron.
Or
Discuss reactivity of different
metals in reactivity series with water.
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Draw a labelled diagram of an
electric motor. Explain its principle and working. What is the function of
split ring in an electric motor?
Or
Explain the underlying principle and
working of an electric generator by drawing a labelled diagram. What is the
function of brushes?
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