Question

When Sunita class XII student came to know that her parents were planning to rent out the top floor of their house to a mobile company she protested. She tried hard parents to convince her parents that this move would be a health hazard ultimately her parents agreed:
1). In what way can setting up a 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?
Estimate the range of em waves which can be transmitted by an antenna of height 20 m.
(Given the radius of the earth is 6400 km )

Answer 1

Hint: The transmission tower increases the radiation and hence damages the health of the bird and the people nearby in the long term and the range of the em waves which can be transmitted using the antenna can be calculated as using the formula for the range of the antenna given by $\sqrt{2hR}$

Complete step-by-step solution:
Part 1
The setting up of the transmission tower increases the chances of the increased deaths of the birdlife in the atmosphere nearby and they are potential health hazards.
Some facts are being established that the radiation effects from the cell towers are linked to the brain cancers in the human beings and these high structures can even confuse the birds which primarily move using the sonic signals in the night.
So there are many ways in which the setting up of the transmission tower in residential colonies prove to be harmful to health.

Part 2
Sunita has applied her knowledge in real life. She studied her concepts from the books and learned the facts and concepts from the class and used her knowledge and stopped her parents from being damaged and saved a community from several health hazards.
She not only saved the region from the health hazards but also she educated her parents and was able to convince them which is commendable.
So here Sunita displayed her capability of applying the concepts she learned in real life.

Part 3
Now we are given the height of the antenna as 20m
We know the range of the antenna is given by the expression as:
Range of the antenna is: $\sqrt{2hR}$ where h is the height of the antenna and R is the radius of the earth and we get the value of the range as :
The radius of the earth is 6400 km so
Range = R = $\sqrt{2hR}$ = $\sqrt{2 \times 20 \times 6400 \times 1000}$ = $16 \times 1063 m$ = 16 km
So we found the range of the antenna as 16 km.

Note: The concept of the birds dying due to the increased cell towers is not yet scientifically proven but many people strongly believe that the towers are one of the main reasons for the disappearance of the birds and increased cancers and other health hazards. Even though the radiation from the towers is not so harmful we need to be very careful about the hazards.