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प्रश्न
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 e.m. waves which can be transmitted by an antenna of height 20 m. (Given radius of the earth = 6400 km)
उत्तर
(1) A transmitting tower makes use of electromagnetic waves 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 ×105 m
`d=sqrt(2xx20xx64xx10^5)`
d = 16000 m
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संबंधित प्रश्न
Arrange the following electromagnetic wave in the order of their increasing wavelength:
(a) γ- rays
(b) Microwaves
(c) X-rays
(d) Radio waves
Identify the electromagnetic waves whose wavelengths vary as:
(a) 10–12 m < λ < 10–8 m
(b) 10–3 m < λ < 10–1 m
Write one use for each.
What is the ratio of the speed of gamma rays to that of radio waves in a vacuum?
Which segment of electromagnetic waves has highest frequency? How are these waves produced? Give one use of these waves.
How does oscillating charge produce electromagnetic waves?
State any one property which is common to all electromagnetic waves.
What are electromagnetic waves?
The speed of plane electromagnetic waves is maximum in ______.
Light with an energy flux of 20 W/cm2 falls on a non-reflecting surface at normal incidence. If the surface has an area of 30 cm2 the total momentum delivered (for complete absorption) during 30 minutes is ______.
Professor C.V Raman surprised his students by suspending freely a tiny light ball in a transparent vacuum chamber by shining a laser beam on it. Which property of EM waves was he exhibiting? Give one more example of this property.
