1. 1. Which characteristic of electromagnetic (EM) energy is common to all energies in the spectrum? Wavelength, frequency, amplitude, or velocity. 2. Describe an electromagnet. How does it differ from a solenoid? 3. What is impedance? 4. What is an atomic mass unit based on? 5. Does an electron have mass? 6. When describing characteristics of photon energy with a sine wave, what factors are inversely proportional to each other? 7. What is the difference between periods and groups on the periodic table? 8. How many electrons can potentially fill all of the orbital shells if the outermost shell is 3 (or m) 9. Potassium has an atomic number of 19. How many electrons will it have in its outermost shell? 10. Using Ohm’s law, when there are 9 V and 3 ohms what is the amperage? 11. Is it voltage, amperage or resistance that causes a spark to jump a gap? 12. P=I V What is this the formula for? What is the unit of measurement? 13. What is thermionic emission? 14 A motor converts what kind of energy to what kind of energy? 15. What is the purpose of a rectifier circuit in the circuitry of the x-ray tube. 16 At what angles of the sine wave is the signal at zero, max, zero, max, and zero again? 17. What is the purpose of an electrical transformer? 18. What do we know about a transformer with 1000 windings in the primary and 500 winding in the secondary? 19. Current in an x-ray tube flows through two electrodes, the negative _______ and the positive _____. Review #2: Chapters 3 and 4

2. 1. Which characteristic of electromagnetic (EM) energy is common to all energies in the spectrum? Wavelength, frequency, amplitude, or velocity. Velocity 2. Describe an electromagnet. How does it differ from a solenoid? A solinoid is a coil with a current passing through it. Add an iron core and it’s an electromagnet. 3. What is impedance? resistance 4. What is an atomic mass unit based on? 1/12 the atomic mass of a carbon 12 atom 5. Does an electron have mass? Yes, though very little (.000548 AMU) 6. When describing characteristics of photon energy with a sine wave, what factors are inversely proportional to each other? Frequency and wavelength 7. What is the difference between periods and groups on the periodic table? Periods are atoms with the same outermost principle number shell, groups are atoms with the same valence number of electrons. 8. How many electrons can potentially fill all of the orbital shells if the outermost shell is 3 (or m) 2 + 8 + 18 = 28 9. Potassium has an atomic number of 19. How many electrons will it have in its outermost shell? One. Two in 1st shell, 8 in second shell, 8 in the third shell (octet rule) and one in the 4th shell. Review #2: Chapters 3 and 4 10. Using Ohm’s law, when there are 9 V and 3 ohms what is the amperage? Ohm’s law: V=IR, or in this case I=V/R or 9/3 = 3 amps. 11. Is it voltage, amperage or resistance that causes a spark to jump a gap? Voltage (potential difference) 12. P=I V What is this the formula for? What is the unit of measurement? Electrical power, measured in watts, or kilowatts. 13. What is thermionic emission? The process of adding energy to atoms in a filament, lowering their binding energy and creating a space charge 14 A motor converts what kind of energy to what kind of energy? electrical to mechanical 15. What is the purpose of a rectifier circuit in the circuitry of the x-ray tube. To change AC to DC 16 At what angles of the sine wave is the signal at zero, max, zero, max, and zero again? 0, 90, 180, 270, 360 degrees 17. What is the purpose of an electrical transformer? Raise V lower A (step up). Or lower V and raise A 18. What do we know about a transformer with 1000 windings in the primary and 500 winding in the secondary? It’s a step down transformer with a 2:1 ratio. Voltage and amperage will be inversely transformed by a factor of 2. 19. Current in an x-ray tube flows through two electrodes, the negative cathode and the positive anode.