Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots.”
So D is your answer
Transmission of information in ANY form can be done digitally
or analoguely.
Beginning about 30 years ago, everything slowly started changing
to digital. Today, all commercial satellite communication, all optical
fiber communication, all internet communication, all computer
communication, all commercial cable communication, all commercial
television, and much of the telephone system, are all digital.
On your computer ... .pdf, .jpg, .mp3 etc. are all digital methods of
moving and storing information.
AM and FM radio are an interesting subject. They're all still analog.
They could easily be changed to all digital, and it would be a big
improvement, both for the broadcasters and for the listeners.
BUT ... every AM and FM radio that anybody has now would be
obsolete. Every single radio would either need to be replaced,
OR you'd need to add a digital decoder to every radio, like we
had to do with our TV sets a few years ago when television
suddenly became all digital. With AM and FM radios, the decoders
would be bigger, and would cost more, than most of the radios.
And that's why commercial radio broadcasting is still analog.
Answer:
the maximum intensity of an electromagnetic wave at the given frequency is 45 kW/m²
Explanation:
Given the data in the question;
To determine the maximum intensity of an electromagnetic wave, we use the formula;
= 
ε₀cE
²
where ε₀ is permittivity of free space ( 8.85 × 10⁻¹² C²/N.m² )
c is the speed of light ( 3 × 10⁸ m/s )
E is the maximum magnitude of the electric field
first we calculate the maximum magnitude of the electric field ( E )
E = 350/f kV/m
given that frequency of 60 Hz, we substitute
E = 350/60 kV/m
E = 5.83333 kV/m
E = 5.83333 kV/m × ( 
)
E = 5833.33 N/C
so we substitute all our values into the formula for intensity of an electromagnetic wave;
= ε₀cE²
= × ( 8.85 × 10⁻¹² C²/N.m² ) × ( 3 × 10⁸ m/s ) × ( 5833.33 N/C )²
= 45 × 10³ W/m²
= 45 × 10³ W/m² × ( 
)
= 45 kW/m²
Therefore, the maximum intensity of an electromagnetic wave at the given frequency is 45 kW/m²
As we can see that the boy is moving his hand up and down while producing the wave in the string.
Here we can see that the source of disturbance or source of wave here in this example is the boy who is holding the string at one end.
So here the motion of the hand of boy is representing the motion of medium molecules in the medium always
So here the disturbance of wave is travelling in the string to the right direction while if we see the direction of medium molecules then it is moving perpendicular to the string i.e. up and down
This type of wave is known as transverse waves in which medium molecules moves perpendicular to the direction of wave
