click below
click below
Normal Size Small Size show me how
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 |