Question

When Sunita, a class XII student, came to know that her parents are planning to rent out the top floor of their house to a mobile company she protested. She tried hard to convince her parents that this move would be a health hazard.
Ultimately her parents agreed:
(1) In what way can the setting up of transmission tower by a mobile company in a residential colony prove to be injurious to health?
(2) By objecting to this move of her parents, what value did Sunita display?
(3) Estimate the range of em waves which can be transmitted by an antenna of height 20 m. (Given radius of the earth = 6400 km)

Answer 1

(1) A transmitting tower makes use of electromagnetic wave such as microwaves, exposure to which can cause severe health hazards like tumour and cancer. Also, the transmitting antenna operates on a very high power, so the risk of someone getting severely burnt in a residential area increases.
(2) By objecting to this move of her parents, Sunita has displayed awareness towards the health and environment of her society.
(3) Range of the transmitting antenna.
$d=\sqrt{2hr}$
Here, h is the height of the transmitting antenna and R is the radius of the Earth.
R = 6400 km= $64\times {10}^5$
$d=\sqrt{2\times 20\times 64\times {10}^5}=16000m$