The Physics of an AM Radio
It’s was a beautiful sunny morning and Bill just kissed his wife goodbye and headed out the door on his way to work. As Bill got into his car he realized that he missed the Utah Jazz game the night before because of a late business meeting and fell asleep before the news came on so he couldn’t catch the highlights or even the score. He remembered that he could catch the rundown on AM frequency 930 (Sports News Radio).
Many people enjoy listening to AM radio because of how convenient it is to listen and catch up on the sports, weather or just enjoy the entertainment of listen to Rush or Dr. Laura, but are much like Bill and don’t have any idea how the signal that carries these programs is sent or even received. In an attempt to understand this process, Bill confronts a part time employee who is currently studying electronics and has a basic knowledge of how the AM radio found his car or even his home works.
Almost all AM radios work under the same basic design. There are two very simple yet very important things that make AM radio possible. What are these things? A transmitter(the station) and a receiver(the radio).
THE TRANSMITTER
Each radio station that desires to have a frequency(signal) on AM radio must notify the FCC and are assigned a frequency that they can use to send their information out on. The very first part of the transmitter is a quartz crystal. This is used because it is very stable and efficient which is important because there are certain laws and guidelines that the stations must abide by. They cannot go over or below the assigned frequency by more than 5K hertz, making a bandwidth of 10K hertz. After the quartz crystal, is an oscillator where the actual physics of the transmitter comes in. The oscillator is made up of a variety of electronics components including an operational amplifier and a combination of resistors and capacitors.
Resistors are defined as-The impedance to the flow of electric current. The resistance is equal to the voltage across the object divided by the current through it. Measured in volts per ampere, or ohms.(Physics, A World View 513)
Current is defined as-A flow of electric charge. Measured in amperes. (Physics, A World View 513)
A combination of a resistor and capacitor in series or parallel is called a filter.
...ychedelics no longer shed light on the possibility of peace but instead the insanity of a social world.
Homelessness in America has always been an issue. There have been plans to help solve this issue in San Antonio, Texas, but it does cost local taxpayers millions. It is a tricky situation to solve because some people are innocent and have no other solution to help solve their necessitous situation. Although many people who are impoverished may not be bad, we should eradicate the chronically homeless because many of them are without a roof for their decisions or blameful addictions they can not control and is costing San Antonio’s taxpayers millions.
Homelessness in the United States has been an important subject that the government needs to turn its attention to. There has been announced in the news that the number of the homeless people in many major cities in the United States has been increasing enormously. According to United States Interagency Council on Homelessness reported that there was an estimation of 83,170 individuals have experienced chronic homelessness on the streets of the United States’ streets and shelters on only a single night of January 2015, which is a small decrease of only 1% from the previous year (People Experiencing Chronic Homelessness, n.d.). The United States must consider this subject that most of the people underestimate it and not pay attention
Chronologically the North Korean Nuclear Program stems from the early 1950s; however, the program has its deeper origin back in 1989 during the conclusion of the Cold-War era. The year 1989 marked the deterioration of the Union of Soviet Socialist Republics (USSR) as the primary financial supporter of North Korea. The North Korean nuclear program can be simplified into approximately four different phases over time; moreover, the chronologies of these four main phases predominantly address the unresolved tension between the United States of America and North Korea. This timeline also involves the influences of the other participants of the Six-Party Talks (which comprises of and is not limited to China, Russia, South Korea, and Japan). From 1956 to 1980 phase one was first and foremost the preparation and gathering of scientific knowledge to advance nuclear measures. Then from 1980 to 1994 phase two dealt with the progression and subsequent disruption of North Korea’s national plutonium manufacturing program. The years 1994 to 2002, or phase three, are the overlapping periods of the nuclear freeze that halted domestic production of radioactive material for military purposes. Finally phase four (from early 2002 to current times) covers the present concerns for North Korea returning to nuclear programs.
Homeless individuals are known for taking hand outs and they prefer to plead for money rather than to go work for it. People assume most of the the money that is given to homeless people they spend it on drugs and alcohol because of the fact that many homeless people have drug and alcohol addictions. It is not uncommon to come across homeless youth and older homeless population that are known to abuse substances like drugs and alcohol. Because of the fact that homeless people have substance abuse problems, they tend face illnesses and infections. Many hard working Americans ask themselves “why don’t homeless people just get jobs?” The assumption is they are just lazy and unmotivated. Homeless people choose to live the life they live. Everyone goes through problems but not all people take the path homeless people do. The problems homeless people face is not an excuse for them to be helped and maintained by other hard working people. Although homelessness might be a choice to some, no one knows the hardships these people have gone through. Some assume these people are just lazy but in reality a lot of these homeless people have jobs of their own, they just can’t afford housing and a decent life. Everyone has their own opinion on homeless people, but that does not change the fact that one should still serve the homeless. Not because homeless people need help but because we are
Autism, like cerebral palsy or epilepsy is not a single disease. It is a name given to behavioral phenotype that may have many etiologies. The word autism is derived from a Greek word “autos” which means “self”. Thus autism meant ‘isolated self’. Eugen Bleuler, a Swiss psychiatrist, was the first person to use the word autism. He started using it around 1911 to refer to a group of symptoms of schizophrenia. In 1942 researchers started using the term Autism to describe children with emotional or social problems.
Homelessness in America is almost an epidemic. There are millions of people in the United States alone who suffer from homelessness, meaning they are without, a roof over their head at night, and without food. Many people just overlook it, and don’t realize how big of an issue this really is. Being homeless just doesn’t happen in a specific part of the United States, it happens everywhere across the country, even in the places you would never expect. It happens in the wealthiest of places, and the poorest of places, one place being Newark, Ohio, and the local communities surround it. With it being so close to where we live, there is so much we could be doing to help those who are suffering from it, but instead we drive right by them not even
...on I don’t think enough is being done to help the homeless and it’s not all the churches and governments faults. We as their fellow Americans don’t do enough. We think we are superior to them, and act as if they don’t exist, or don’t have feelings. If you have some spare change in your pocket why not just give it to them? If you were in there position I’m sure you would want someone to do it for you! And many of us have clothes in our closet we no longer fit or no longer like, why not drop them off at the Salvation Army? There is someone out there who would be grateful for something clean to wear. Or how about you just give a friendly smile at a homeless person when you walk down the street, that just might brighten up there whole day. It will definitely take a lot of work to end homelessness but the first step is giving them the respect they deserve as citizens.
Baron-Cohen, S., Ring, H.A., Bullmore, E. T., Wheelwright, S., Ashwin, & Williams, S. C. R. (2000). The amygdala theory of AUTISM. Neuroscience. Behavior Review, 24, 434-438.
Many inventions have impacted the world throughout history but in my opinion one of the most impactful one’s was the invention of the radio . This invention provided society with many things which include entertainment, communication, and easier access to information. Radio is still a central part of the society today but just like any other invention radio has an interesting history of how it progressed through time.
We have been aware of autism since the early 1900’s. Autism was very rare until the mid-1960’s. According to the article History of Autism by the website WebMD, “The word ‘autism,’ which has been in use for about one hundred years, comes from the Greek word ‘autos,’ meaning ‘self.’ The term describes conditions in which a person is removed from social interaction -- hence, an isolated self.” Eugen Bleuler was the first to use this word in 1911, when he referred to a group of schizophrenias. It was not until the 1940’s when the United States researchers started using the word “autism” to ...
... Considering the great number of homeless people in this country and more specifically in this county, there aren’t enough people who care to balance it out. The annual estimates show reports that the amount of homeless people is decreasing but at an extremely slow rate. The more society is forced to witness people sleeping on the streets and to make the decision to pass them by or spare 50 cents the greater the hostility toward them will grow. It begs the question of where all of the funding goes and why the reduction in the number of people on the streets isn’t higher. There needs to be more done than simply walking the street, counting the number of people seen, especially if a reduction is noted but can’t be explained. Unless more people get involved with this issue the status quo will remain the same, leaving millions to continue sleeping on the street.
All useful generators of electricity come in two basic forms, alternating current and direct current. Direct current (dc) comes from generators that do not change in polarity, always producing a positive charge. In alternating current (ac) the polarity of the terminals is always changing from positive to negative. Thus you are left with alternating current flow. There are different ways of measuring and generating alternating and direct current.
By the time the 20th century arrived, vacuum tubes were invented that could transmit weak electrical signals which led to the formation of electromagnetic waves that led to the invention of the radio broadcast system (750). These vacuum tubes were discovered to be able to transmit currents through solid material, which led to the creation of transistors in the 1960’s (750).
Frequency modulation is, of course, used on the FM band. And it is used for