The Electro Magnetic Spectrum Radio Waves Radio waves are made by various types of transmitter, depending on the wavelength. They are also given off by stars, sparks and lightning, which is why you hear interference on your radio in a thunderstorm. Radio waves are the lowest frequencies in the electromagnetic spectrum, and are used mainly for communications. Radio waves are divided into:- [IMAGE]Long Wave, around 1~2 km in wavelength. The radio station "Atlantic 252" broadcasts here. [IMAGE]Medium Wave, around 100m in wavelength, used by BBC Radio 5 and other "AM" stations. [IMAGE]VHF, which stands for "Very High Frequency" and has wavelengths of around 2m. This is where you find stereo "FM" radio stations, such as "Galaxy 101" and "GWR FM". Further up the VHF band are civilian aircraft and taxis. [IMAGE]UHF stands for "Ultra High Frequency", and has wavelengths of less than a metre. It's used for Police radio communications, military aircraft radios and television transmissions. Large doses of radio waves are believed to cause cancer, leukaemia and other disorders. Some people claim that the very low frequency field from overhead power cables near their homes has affected their health. Microwaves Microwaves are basically extremely high frequency radio waves, and are made by various types of transmitter. In a mobile phone, they're made by a transmitter chip and an antenna, in a microwave oven they're made by a "magnetron". Their wavelength is usually a couple of centimetres. Stars also give off microwaves. Microwaves cause water and fat molecules to vibrate, which makes the substances hot. Thus we can use microwaves to cook many types of food. Mobile phones use microwaves, as they can be generated by a small antenna, which means that the phone doesn't need to be very big. The drawback is that, being small, they can't put out much power, and they also need a line of sight to the transmitter. This means that mobile phone companies need to have many transmitter towers if they're going to attract customers.
Millions of people around the world use cell phones on a daily basis and people hardly realize the terminal risks. Cell phones may seem completely harmless, but they actually emit radio waves that can be hazardous towards the human body. Each time someone makes a call or receives a call, a type of cancerous radiation is given off by the cell phone in order for the user to communicate with the person on the other side of the line. Since the amount of cell phone users has rose rapidly, more people are being exposed to this kind of radiation. As cell phones undergo advancements, people are starting to use them more often, leading to an increase in the amount and length of calls each day. Some believe that these radio waves do no such harm to your body due to the radiation wave being weak but in reality, exposure to any kind of radiation is never safe. Radio waves might not affect the human body immediately, but after a long period of time the effects are bound to reveal. Cell phones can increase the risk of cancer because its radiation affects brain cells, causes tumors, and is hazardously absorbed by the tissues in the body.
Electric guitars are devices that generate sound from a set of pickups that convert string vibration into electrical signals for amplification. The sound starts out as vibrations the musician creates while playing. These vibrations are picked up by the pickups of the guitar. What are pickups? Pickups are permanent magnets wrapped around in a coil. Since the strings are made with a special material called ferromagnetic, they interact with the magnetic fields in the pickups and force electrons to move in the loop. Moving electrons can generate a signal that can be read by the amplifier.
In 1998 a Maryland neurologist, Dr. Christopher Newman, was diagnosed with brain cancer and he could no longer work as a result of his disease. He claimed that the Motorola cell phone he had in 1992 to keep in touch with his patients gave him cancer. Then in 2000, he filed an $800 million lawsuit against several wireless providers including Motorola Inc., Verizon Communications Corp., Bell Atlantic Mobile Systems, and others. Within a month, the U.S. District Judge Catherine Blake dismissed the case due to lack of evidence. This case happened during a time where people were confused about how electromagnetic radiation affects the human body. Fast-forward to today and there is still confusion. A lot of people today feel like they are at risk from developing cancer from electronic devices like cell phones, microwaves, and laptops. That is simply not true.
Magnetism is very useful in our daily life. A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. In addition, magnetic field is a region which a magnetic material experiences a force as the result of the presence of a magnet or a current carrying conductor. Current carrying conductors also known as wire. As we know there have north pole and south pole of a magnet. If same pole of magnet approaches each other, there will repel each other. In contrast, if different pole of magnet approaches each other, they will attract. These are same with the electric charge, if same charge it will repel, different charge it will attract. Although magnets and magnetism were known much earlier, the study of magnetic fields began in 1269 when French scholar Petrus Peregrinus de Maricourt mapped out the magnetic field on the surface of a spherical magnet using iron needles [search from Wikipedia]. Noting that the resulting field lines crossed at two points he named those points 'poles' in analogy to Earth's poles. Each magnet has its own magnetic field which experiences a force as the result of the presence of a magnet and magnetic field has made up of magnetic field lines. The properties of magnetic field lines is it begin at the north pole and end at the south pole. The north pole always flow out while south pole always flow in. The closer the magnetic field lines, the strength of magnetic field increases. Furthermore, these line cannot cross each other. Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. Ferromagnetic materials...
For the purpose of this assignment the experience of attending Electro-Convulsive Therapy will be discussed. It will include rationale for the procedure, an account of the procedure and the student nurses reflection on the experience using Gibbs’ model of reflection (Jasper 2003). Electroconvulsive therapy (ECT) is a medical treatment for severe mental illness in which a small, carefully controlled amount of electricity is introduced into the brain. This electrical stimulation, used in conjunction with anaesthesia and muscle relaxant medications, produces a mild generalised seizure or convulsion (Mankad et al 2010).
The next type of spectra to look at is Carbon NMR. In Carbon NMR a spectrum is produced that has peaks for each unique carbon in the molecule. Carbon NMR is possible because radio waves are shot through a sample already aligned on a very large magnet and the nuclei of the atoms switch to a higher energy state. It requires different wavelengths to flip different carbons. The locations of the peaks on the spectrum shows what type of functional groups the carbons are part of. Figure 6 shows the Carbon NMR for ibuprofen. In the figure there is a drawing of ibuprofen with the unique carbons numbered. These numbers align to the spectra underneath and the information given in purple. Anywhere from 10-60ppm are alkanes. That means there should have
Cell phones use radio frequencies to transmit signals. Radio Frequencies (RF) are a form of electrical waves similar to those used in radios, microwaves, radars or satellite stations. They are emitted from a transmitter, and received using an antenna. This telephony technology is restricted geographically to small zones called “Cells”. Every cell has a base station capable of sending and receiving radio waves. When a call is started a signal leaves the handheld unit headed to the closest base station. This station answers by allocating a specific channel to the unit. When this “channel” is established, modulated radio frequency signals are both received and transmitted. The head of the user is in the near field of use because the distance from the antenna to the head is a few centimeters. (Blettner & Berg 2000) If the antenna is inside the body of the phone, the exposure to Radio Frequencies is greater. The antenna might be requesting a stronger signal to contest with the interference of the battery or the actual shell of the phone’s body.
The higher the energy level in an energy source, the lower the wavelength of the energy produced, and the higher the frequency. Differences in wave energy characteristics are used to classify electromagnetic energy.
Spectrum refers to the electromagnetic spectrum, which is the range of frequencies through which electromagnetic radiation travels. Electromagnetic radiation is the energy that travels at the speed of light in waves as a stream of photon particles. This form of energy encompasses radio waves, microwaves, visible, nonvisible light, X–rays and gamma rays, and these classifications are based upon the frequency at which the energy travels (see figure 1). In order to refer to a specific portion, also called a band, of the electromagnetic spectrum, one uses Hertz (Hz) as the unit of measurement. Figure 1: Spectrum has an abundance of practical applications.
The cause for this concern, according to the National Cancer Institute, is that cell phones emit radiofrequency energy (radio waves), a form of electromagnetic radiation, and tissues nearest to where the phone is being held can absorb this form of radiation. Electromagnetic radiation is categorised into ionizing and non-ionizing radiation and being exposed to ionizing radiation is known to increase the cancer risk. Even though many studies have researched and examined the potential health effects of non-ionizing radiation there is no consistent evidence that non-ionizing radiation increases cancer risk. Cell phones make use of non-ionizing radiation.
Time-varying electric fields can bring magnetic fields and vice-versa. Since both fields generate each other, they occur jointly and therefore, propagate as electromagnetic waves.
Magnet is any piece of material, with attractive iron (or steel) property. Magnetite, also called magnet, is a naturally occurring rock magnet. This natural magnet was first discovered in a region known as magnesia and was named after the area in which it was discovered. Magnetism may be naturally present in a material or the material may be artificially magnetized by various methods. Magnets may be permanent or temporary. After being magnetized, a permanent magnet will retain the properties of magnetism indefinitely. A temporary magnet is a magnet made of soft iron, that is usually easy to magnetize; however, temporary magnets lose most of their magnetic properties when the magnetizing cause is discontinued. Permanent magnets are usually more difficult to magnetize, but they remain magnetized. Materials which can be magnetized are called ferromagnetic materials. We will talk more about making a magnet later on.
Light is a series of self-propagating transverse waves composed of electric and magnetic fields in a fixed ratio. The distance between the crests of successive waves is known as the wavelength, denoted by the symbol λ (lambda), as shown in Figure 2. The frequency of a wave is defined as the number of waves passing through a given point per second.
Temperature has a large effect on particles. Heat makes particles energized causing them to spread out and bounce around. Inversely the cold causes particles to clump together and become denser. These changes greatly F magnetic the state of substances and can also influence the strength of magnetic fields. This is because it can alter the flow of electrons through the magnet.
It is the reason for the great technological movement of the 21st century. Its applications are used on a day-to-day basis. What is this form of energy? It is electricity. Electricity is defined as a form of energy from the existence of charged particles. The charged particles are either positive or negative (protons or electrons). Moreover, through the same principal, the phenomenon of magnetism is also applied on a day-to-day basis. Magnetism is defined as either an attractive or repulsive force between objects due to an electric charge. To thoroughly understand the strength of electricity and magnets, it is vital to first be cognizant of where and when they were discovered.