Section A
Answer the following question
Q. no. 1 to 13 (within the limit of 10 to 20 words) as directed: (1 mark each)
1. What do you mean by free fall?
2.
What do you mean by acceleration Q due to gravity?
3.
What are the differences between the mass of an object and its weight?
4.
What do you mean by buoyancy?
5.
Why does an object float or sink when placed on the surface of water?
6.
Define 1 J of work.
7.
What is the kinetic energy of an object?
8.
How does the sound produced by a vibrating object in a medium reach your ear?
9.
What do we get from cereals, pulses, fruits and vegetables?
10.
How does the atmosphere act as a blanket?
11.
What causes winds?
12.
How are clouds formed?
13.
List any three human activities that you think would lead to air pollution.
Section B
Answer the following question
Q. no. 14 to 27 (within the limit of 40 to 50 words) directed (2 marks each).
14.
Relative density of silver is 10.8. The density of water is 103 kg m–3
. What is the density of silver in SI unit?
15.
A porter lifts a luggage of 15 kg from the ground and puts it on his head 1.5 m
above the ground. Calculate the work done by him on the luggage.
16.
Find the energy possessed by an object of mass 10 kg when it is at a height of
6 m above the ground. Given, g = 9.8 m s–2
17.
What are the different means by which infectious diseases are spread?
18.
What are the immunisation programmes available at the nearest health center in
your locality? Which of these diseases are the major health problems in your
area?
19.
How do biotic and abiotic factors affect crop production?
20.
What are macro-nutrients and why are they called macronutrients?
21.
What are the advantages of composite fish culture?
22.
What are the desirable characters of bee varieties suitable for honey
production?
23.
What is pasturage and how is it related to honey production?
24.
What is the major source of fresh water in the city/town/village where you
live?
25.
Do you know of any activity which may be polluting this water Q source?
26.
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of acetic acid. The
products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium Q
acetate. Show that these
27.
Calculate the formula unit mass of CaCl2 .
Section C
Answer the following question
Q. No. 28 to 53 in short (within the limit of 60 to 80 words) as directed: [3 marks each)
28.
What is the importance of universal law of gravitation?
29. An
object of mass 15 kg is moving with a uniform velocity of 4 m s–1. What is the
kinetic energy possessed by the object?
30.
A boy of mass 50 kg runs up a staircase of 45 steps in 9 s. If the height of
each step is 15 cm, find his power. Take g = 10 m s–2 .
31.
An electric bulb of 60 W is used for 6 h per day. Calculate the ‘units’ of
energy consumed in one day by the bulb.
32.
A sound wave has a frequency of 2 kHz and wave length 35 cm. How long will it
take to travel 1.5 km?
33.
A person clapped his hands near a cliff and heard the echo after 2 s. What is
the distance of the cliff from the person if the speed of the sound, v is taken
as 346 m s–1?
34.
Why should preventive measures and biological control methods be preferred for
protecting crops?
35.
What factors may be responsible for losses of grains during storage?
36.
What management practices are common in dairy and poultry farming?
37.
What are the differences between
broilers and layers and in their management?
38.
Explain any one method of crop production which ensures high yield.
39.
What are the different states in which water is found during the water cycle?
40.
Name two biologically important
compounds that contain both oxygen and nitrogen
41.
List any three human activities which would lead to an increase in the carbon
dioxide content of air.
42.
What is the greenhouse effect?
43.
What are the two forms of oxygen found in the atmosphere?
44.
Why is the atmosphere essential for life?
45.
Why is water essential for life?
46.
Which would require a greater force –– accelerating a 2 kg mass at 5 m s–2
or a 4 kg mass at 2 m s-2 ?
47.
A girl of mass 40 kg jumps with a horizontal velocity of 5 m s-1
onto a stationary cart with frictionless 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
48.
Which do you think is a more basic characteristic for classifying organisms?
(a) the place where they live.
(b) the kind of cells they are made of.
Why?
49.
On what bases are plants and animals put into different categories?
50.
What are the major divisions in the Plantae? What is the basis for these
divisions?
51.
How are the criteria for deciding divisions in plants different from the
criteria for deciding the subgroups among animals?
52.
Write name of following formulae:
(i) CaCO3
(ii) CaCl2
(iii) K2 SO4
(iv) KNO3
53.
Calculate the formula unit masses of ZnO, Na2O, K2CO3
, given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O
= 16 u.
Section D
Answer the following question
Q. No. 54 to 71 in detail (within the limit of 90 to 120 words) as directed (4 marks each)
54.
A block of wood is kept on a tabletop. The mass of wooden block is 5 kg and its
dimensions are 40 cm × 20 cm × 10 cm. Find the pressure exerted by the wooden
block on the table top if it is made to lie on the table top with its sides of
dimensions (a) 20 cm × 10 cm and (b) 40 cm × 20 cm.
55.
What is the work to be done to increase the velocity of a car from 30 km h–1
to 60 km h–1 if the mass of the car is 1500 kg?
56.
Two girls, each of weight 400 N climb up a rope through a height of 8 m. We
name one of the girls A and the other B. Girl A takes 20 s while B takes 50 s
to accomplish this task. What is the power expended by each girl?
57.
A ship sends out ultrasound that returns from the seabed and is detected after
3.42 s. If the speed of ultrasound through seawater is 1531 m/s, what is the
distance of the seabed from the ship?
58.
Under which of the following conditions are you most likely to fall sick?
(a) when you are taking examinations.
(b) when you have travelled by bus and
train for two days.
(c) when your friend is suffering from
measles. Why?
59.
Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds, do not
adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt
irrigation and use fertilizer.
(c) Farmers use quality seeds, adopt
irrigation, use fertilizer and use crop protection measures.
60.
For increasing production, what is common in poultry, fisheries and bee-keeping?
61.
How do you differentiate between capture fishing, mariculture and aquaculture?
62.
We know that many human activities lead to increasing levels of pollution of
the air, water-bodies and soil. Do you think that isolating these activities to
specific and limited areas would help in reducing pollution?
63.
Write a note on how forests influence the quality of our air, soil and water
resources.
64.
A constant force acts on an object of mass 5 kg for a duration of 2 s. It
increases the object’s velocity from 3 m s–1 to 7 m s-1. Find the magnitude of
the applied force. Now, if the force was applied for a duration of 5 s, what
would be the final velocity of the object?
65. Write
short note about CHARACTERISTICS OF A SOUND WAVE
66.
A motorcar is moving with a velocity of 108 km/h and it takes 4 s to stop after
the brakes are applied. Calculate the force exerted by the brakes on the
motorcar if its mass along with the passengers is 1000 kg.
67.
A bullet of mass 20 g is horizontally fired with a velocity 150 m s-1 from a
pistol of mass 2 kg. What is the recoil velocity of the pistol?
68.
Explain how animals in Vertebrata are classified into further subgroups.
69.
Write down the formulae of
(i) sodium oxide
(ii) aluminium chloride
(iii) sodium suphide
(iv) magnesium hydroxide
70.
Calculate the number of moles for the following: (i) 52 g of He (finding mole
from mass) (ii) 12.044 × 1023 number of He atoms (finding mole from
number of particles).
71.
Calculate the mass of the following: (i) 0.5 mole of N2 gas (mass
from mole of molecule) (ii) 0.5 mole of N atoms (mass from mole of atom) (iii)
3.011 × 1023 number of N atoms (mass from number) (iv) 6.022 × 1023
number of N2 molecules (mass from number)
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