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physics 4&5
| Question | Answer |
|---|---|
| an xray photon is a quantum of what | electromagnetic energy |
| what is another name for a photon | quantum |
| how is energy related to its frequency | directly |
| what are the 4 properties of a photon | frequency, wavelength, velocity and amplitude |
| what does the symbol C represent | velocity 3x10^8 m/s |
| what is the rate of the rise and fall of a sine wave | frequency |
| what is the range fom crest to valley called in a sine wave | amplitude |
| wht is the number of wavelengths that pass a point of observation per second | frequency |
| how is frequency measured | hertz |
| wavelength and frequency are________ proportional | inversely |
| reduction in intensity that results from scattering and absorption | electromagnetic energy attenuation |
| why is the intensity of radiation reduced with distance | because it is spread out over a greater distance |
| photon energy is ______proportional to its frequency | directly |
| what is planck's constant | 4.15x10^-15 |
| what is planck's equation | E=HF E-energy, H-planck"constant, F-frequency |
| what is the diagnostic xray range | 30-150 kvp |
| what is the research range | <10kvp |
| matter can be transformed into _____ and energy can be transformed into_____ | energy, matter |
| what is the relativity formula | E=MC^2 |
| waht is the highest range of energy | gamma rays |
| what is the lowest range of energy | radiowaves |
| wht type of rays are produced in the nucleus of the atom | gamma rays |
| what type of rays are produced outside of the nucleus | xrays |
| when will photons act with matter most easily | when the matter is close tto the same size of the photon wavelength |
| what is the study of stationary electric charges | electrostatics |
| what is the smallest unit of electrical charges | electron |
| electrification occurs through the movement of what | electron |
| what are the electrostatic laws | unlike charges attract and like repel/ electric is uniform or throughout the surface/ electric charge of a conductor is concentrated along the sharpest curvature of the surface |
| what is coulombs law | the electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them |
| what is the study of electric charges in motion | electrodynamics |
| what is the substance in which electrons flow easily | conductor (metals, water, copper being the best |
| what does not allow electrons to flow easily | insulators (glass, clay, and other earthlike materials) |
| what acts as a insulator or conductor depending on the conditions | semiconductor (silicon, germanium |
| waht are the conditions that cause a semiconductor to act as a insulator or conductor | temperature |
| what happens to current when resistance to electric increases | reduces the current |
| what is an electric current | controlled resistance in a conductor, and the conductor is a closed path |
| What is the formula for ohms law | V=IR V=volts or electrical potential I=electrical current or amps and R=electric resistance or ohms |
| what is a series circuit | all circuit elements are connected on a line of the same conductor |
| what is a parallel circuit | elements are connected at the ends rather than lying on a line of a conductor |
| what is a current | flow of electrons through a conductor |
| what is a D/C current | direct current and produced by a baattery and the electrons flow in one direction |
| what is a A/C current | current produced by a generator. electrons flow alternately in opposite direction (basically anything that has to be plugged in) |
| in the US how long does it take a A/C to go through a complete cycle | 1/60 second |
| how is the electrical charge distributed | evenly throughout |
| where do charges concentrate on a electrified object | sharpest curvature |
| volt is the unit of | electric potential |
| voltage is another name for what | electric potential |
| electric power is measured in | watts |
| what is required for common household appliances | 500-1500 watts |
| what does a charged particle in motion create | magnetic field |
| what is magnetism measured in | tesla |
| the lines of a magnetic field are always | closed loops |
| what is accumulation of dipoles | magnetic domain |
| lines of magnetic field that do not start or end | bipolar |
| small magnet created by the electron orbit | dipole |
| natural magnet | earth |
| water and plastic are examples of what type of magnetic material(repelled by either pole) | diamagnetic |
| magnetic material that is strongly attracted when placed in a external magnetic field | ferromagnetic |
| magnetic material that is slightly attracted by external magnetic field | paramagnetic |
| what is a solenoid | coil of wire |
| what changes the intensity of alternating voltage and current | transformer |
| sinusoidal fashion | wavelike |
| three imaging windows | xray imaging, visual imaging, MR imaging |
| what wattage do light bulbs require | 30 to 150 |
| what wattage do xray machines require | 20 to 150 |
| what is the older SI unit of magnetic field strength | guass |
| the magnitude of the induced current depends on four factors | faradays law |
| four factors of faradays law | the strength of the magnetic field velocity of the magnetic field as it moves past the conductor angle of the conductor to the magnetic field number of turns in conductor |
| an electric current is induced in a circuit if some part of that circuit is in a changing magnetic field | electromagnetic induction |
| what changes the intensity of alternating voltage and current | transformer |
| what has one winding and varies both voltage and current | autotransformer |
| what are variations of amplitude over time | sine waves |
| wave equation | wavelength= velocity/frequency |
| electromagnetic wave equation | velocity=frequency x wavelength |
| structures that absorb xray | radiopaque |
| structures that transmit xray | radiolucent |
| electrification can be created by what | contact, friction, induction |
| resistance decreases as the temperature of material_________ | reduced |
| the property of some material to exhibit no resistance below a critical temperature | superconductivity |
| any charged particle in motion creates a | magnetic field |
| what can be made into magnets by induction | ferromagnets |
| electric potential is measured in what | joules per coulomb, or volt |
| current carrying coil of wire wrapped around an iron core, which intensifies the induced magnetic field | electromagnet |