English
Do exercise ‘A’ on page no. 140 of your textbook and
submit on 12-04-17.
Science
Save the following
content and draw images of the following bridges as discussed in class under each.
Submit the same on Sunday, 16/4/17.
Utility of Bridges
The
bridges are very useful. They help to:
avoid traffic jam
cut down traffic
shorten trade routes
reduce travelling time
Structure
of the bridge is an important factor. It determines the Quality and strength of
the
bridge.
Types of Bridge
1.
Girder Bridge or Beam Bridge: It is the simplest and the oldest type of
bridge. It is made of horizontal beams called girders. These are supported by
pillars at each end. The pillars bear the load of the beam. In a modern beam
bridge, large numbers of pillars are used to support the beam. So the bridge
does not become weak. The flyovers and the pedestrian bridges are examples of
beam bridge.
2.Cantilever bridge: It
is a balanced projecting structure built using cantilevers. Cantilever is a
horizontal beam supported at one end. It carries the load on the other end or
along its length.
3.
Arch bridge: It is an old type of bridge but very strong. It is
characterized by semicircular structures called arches. It spreads weight
outwards and downwards around the whole length of each arch. Earlier, these
bridges were made of stones and bricks. Now they are made of steel, concrete
and bricks.
4.
Suspension bridge: It is the longest type of bridge. It is used to span
wide rivers or bays. It is made using strong cables. The cables that support
the bridge are made from strong steel wires twisted together. These cables hang
from high towers on either side of the bridge. The modern suspension bridge can
be more than 2km long.
For example, Akashi Kaikyo in Japan is the
longest suspension bridge in the world.
5.
Cable stayed bridge: It is similar to the suspension bridge. It is also
supported by cables. But in this type of bridge, less cable is used. Also the
towers holding the cables are shorter.
6.
Bamboo bridge. It is found commonly in villages. It is built across a
stream. The trees logs are used as pillars. The flat wooden pieces are tied to
the pillars using ropes.
S.St
Continue
these notes in your S.St. notebook and submit on 12/4/2017.
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Q.5.
What is global warming? What is its effect on earth?
A. Global warming refers to an average
increase in the Earth's temperature, which in turn causes changes in climate
pattern. It is caused due to human activities.
When
the earth becomes warmer, it may lead to changes in rainfall patterns, rise
in sea level, and affects plants, wildlife, and humans.
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Q.6.
Write a note on festivals.
·
A festival is an event which is celebrated
collectively for celebrating a cause. Festivals are classified into three –
National festivals, Harvest festivals and Religious festivals.
·
Festivals are mostly celebrated to propagate the
cultural heritage of nations, promote patriotism and brotherhood.
·
It leads to cultural exchange between people of
different regions and nations.
·
This strengthens social bonding among people.
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Q.7.
Classify the following festivals under National, Harvest and Religious
festivals.
Ø Christmas
Ø Eid
Ø Republic Day
Ø Thanks Giving Day
Ø Independence Day
