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How are kelvin scale and celsius scale
related to each other?
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Name the term used for
afunctional segment of DNA.
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A force of 10 N produces an acceleration
of
when applied
on an object. What is the mass of the object?
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A teacher has provided
maizegrain, nut grain, wheat grain and potato to a student and asked him to
select a plant material, which would give blue-black colour with iodine solution.
Then what would he select?
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Name the process in which a
solid changes directly into gaseous form on heating without going in liquid
state?
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What do you mean by a resultant force?
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By which process recovery of
salt from salt solution in water can be done?
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What is plasma?
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What is the colour of pure
ammonium chloride?
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Which law is associated with
this activity?
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Substance 'X' was added to a
test-tube containing water and grounded arhar dal to test the presence of
metanil yellow. The colour of solution changed to pink. Identify 'X'.
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A mixture of iron filings and
sulphur is heated. What colour change in the mixture will appear?
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When sodium sulphate and barium chloride
a solutions are mixed in atest-tube. What do you observe? Give chemical
reaction also.
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A group of students recorded the
following readings while performing the experiment to calculate the percentage of
water absorbed by raisins.
Mass of dry raisins = 2.0 g
Mass of raisins after absorbing
water =3.0 g
Calculate the percentage of
water absorbed by raisins.
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Which elements do the following compounds
contain?
(a) Sugar (b)
Common salt
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While preparing a temporary
mount of onion peel cells or human cheek cells, a coverslip is put on the
mounted material on a slide very gently and pressed down. Give reasons.
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Differentiate the following
activities on the basis of voluntary and involuntary muscles.
(a) Jumping of frog
(b) Pumping of the heart
(c) Writing with hand
(d) Movement of chocolate in
your intestine
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Make a pile of similar carom coins
ona table. Then to remove the lower coin without touching the other coins with your
fingers, you may give a sharp horizontal hit at the button of the pile using
sticker.
(a) What will happen if the hit
is strong enough?
(b) What will happen to the remaining
coins once the lower coin is removed?
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(a) 4 g of solute are dissolved
in 36 g of water. What is the mass percentage of the solution?
(b) How can we make a saturated solution
unsaturated?
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What is green maturing? Name
some commonly used green manure crops.
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Compare the force of attraction between
iron, rubber band and chalk.
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Explain what happens, when a
beam of light is passed through a colloidal solution?
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What is cell theory and who
proposed this theory? What modification Virchow made in this theory?
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What will happen if cells are
not organized in tissue?
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(a) If a potted plant is covered
with a glass jar, water vapours appear on the wall of the glass jar. Explain.
(b) What is the function of
cardiac muscle fibre?
(c) Name the cells of bone and cartilage.
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Starting from a stationary
position, Anil paddles his bicycle to attain a velocity of
in 25 s.
Then, heapplies brakes such that he again comes to rest after next 50 s.
Calculate the acceleration of the bicycle in both cases. Also find the total
distance covered by Anil.
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Describe an activity to
demonstrate Newton's third law of motion.
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Glass and china wares are
wrapped in straw or paper before packing. Briefly explain why?
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Shikha buys a few grams of
precious stones in Delhi. She takes them to equator and is surprised to see
that their weight is reduced. She thinks that she has been cheated. She goes back
to the seller and claims the exchange amount. The shopkeeper explains her how
weight differs due tovalue of g. Satisfied Shikha goes back.
(a) List few values of Shikha.
(b) What are the values of
shopkeeper?
(c) How does g vary with
distance?
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Two objects of masses m1
and m2, when separated by a distance d, exertsa force F on each
other. What happens when
(a) value of mass of first is
doubled?
(b) masses of both objects are
doubled?
(c) masses are brought so closer
that distance between them becomes d/2?
(d) the space between the two
objects has no air, i.e., it is complete vacuum?
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(a) What is vermicompost?
(b) Name two crops used for
preparinggreen manure.
(c) What are the characteristics
of storage structure for grains?
(d) Name two nitrogen fixing
bacteria.
(e) Which type of crop is
generally grown between two cereal crops to restore soil fertility?
Or
Figure shows the two crop fields
[plots A and B] have been treated by manures and chemical fertilisers
respectively, keeping other environmental factors same.
Observe the graph and answer the
following questions
(a) Why does plot B show sudden increase
and then gradual decrease in yield?
(b) Why is the highest peak in
plot A graph slightly delayed?
(c) What is the reason for the
different pattern of the two graphs?
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(a) Why do solids have fixed shape and fixed
volume?
(b) Why is air dense at the sea
level?
(c) On melting of ice, there is
decrease involume instead of increase. Why?
(d) What is the binding force
between molecules if a substance is a gas under ordinary conditions of
temperature and pressure?
(e) Why are average kinetic
energies of hydrogen, carbon dioxide and ethane the same at the same
temperature?
Or
(a) When we light an incense
stick (agarbatti) in a corner of our room, why does its fragrance spread in the
whole room quickly?
(b) Liquid A has higher vapour
pressure than liquid B. Which liquid out of A and B will have lower boiling
point?
(c) Name the five states of
matter, which the scientists are now talking of?
(d) What do you understand by
plasma?
(e) Name the Indian physicist,
who worked for a fifth state of matter.
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How will you separate a mixture containing
kerosene and petrol (difference in their boiling points is more than 25°C),
which are miscible with each other?
Or
Benzoic acid is used as a food preservative.
The graph below shows the heating curve for benzoic acid. Study the graph and
answer the following questions
(i) At what time does benzoic
acid begin to
(a) melt? (b)
boil?
(ii) What is the melting point
of benzoic acid?
(iii) What happens to the
temperature while benzoic acid melts?
(iv) What is the physical state
of benzoic acid during the time interval of 35-45 min?
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An athlete completes one round
of a circular track of diameter 200 m in 40 s.
What will be the distance
covered and the displacement at the end of 2 min 20s?
Or
Deduce the following equations
of motion
(i)
(ii)
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Two objects of masses 100 g and
200 g are moving along the same line and direction with velocities of
and
respectively.
They collide and after the collision, the first object moves at a velocity of
Determine
the velocity of the second object.
Or
(i) Explain why is it difficult
to walk on sand?
(ii) Why is the recoil of a
heavy gun, on firing, not so strong as that of a light gun using the same
cartridge?
(iii) A constant force acts on
an object of 5 kg for a period of 2 s. It increases the velocity of an object
from 3 m/s to 7 m/s. Find the magnitude of the applied force. Now if the force
was applied for a period of 5 s, what would be the final velocity of the
object?
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Name the protective tissue of
animal body. State the types of this tissue.
Or
List the characteristics of cork. How is
it formed? Mention its role.
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