Hindi
Study word meanings of Lesson- 14 given in
Hindi Textbook on Page 92 for a review on Thursday, 3/3/16
Science
I.
Draw the diagram into your
science note book.
II.
Answer the questions that follow in your
science note book and submit the same on Sunday, 6/3/16.
Exposure
to the energy from cellular phone towers:
Studies
have shown a drop in the numbers of common house sparrows in many cities
due
to an increase in use of mobile phones. Some studies have shown long-term
impacts
on health and environment reporting negative consequences on immunity,
health,
behaviour, communication and coordination in animals
and
birds.
Electromagnetic radiation from these
communication towers affected bees very badly and reports of adverse effect on
scavenger birds.
Cell
phones communicate with nearby cell towers mainly through radiofrequency (RF)
Waves.
Cell
phone base stations may be free-standing towers or mounted on existing
structures,
such as trees, water tanks, or tall buildings.
The antennas need to be high enough so they
can adequately cover the area. Base stations are usually from 50-200 feet high.
As
people use cell phones to make calls, signals are transmitted back and forth to
the
base
station. The RF waves produced at the base station are given off into the
environment,
where people can be exposed to them.
Some
scientists have expressed concern that living, working, or going to school near
a
cell
phone tower might increase the risk of cancer or other health problems.
To
prevent overlapping of high radiation fields, new towers should not be
permitted
within
a radius of one kilometre of the existing towers.
Q1.
Explain the function of a satellite in the field of communication.
Q2.
List any two adverse effects in the use of mobile phones on living things.
Q3.
What precautions can you take at your
home to minimize the ill effects of cell
phones ?
Q4.Why
should there be a minimum distance between cell phone towers?
