PHSC 1002 - Midterm PLQs

Mod 1:

  • _______ mega → 10^6 (one million)
  • _______ nano → 10^-9 (one billionth)
  • _______ kilo → 10^3 (one thousand)
  • _______ micro → 10^-6 (one millionth)
  • _______ giga → 10^9 (one billion)
  • Which device consumes more energy: a 1.2 kW hair dryer used for 10 mins or a 7W night light left on for 24 hours? → The hair dryer
  • Electricity from a wall outlet in your home cost you about: → a dime per kilowatt-hour
  • Rank the three most common types of light bulbs (CLF, LED, and incandescent) according to their power usage (highest first). Assume that they all generate the same brightness of light. → Incandescent, CFL, LED
  • The power required to supply the energy needs of a typical U.S. household is approximately → 1 kilowatt (1 kW)
  • The conversion efficiency of an inexpensive solar cell in a typical consumer product is closest to → 20%
  • The average human requires a daily intake of approximately how many Calories to maintain a constant body weight? → 2000 Calories
  • The 600-acre “solar farm” operated by Capital Region Solar in West Baton Rouge Parish generates 50 megawatts (50 MW) of power. The company claims that this is sufficient to power 9600 homes. Given these numbers, what is the average power per household provided by the solar farm? → 5 kW
  • Suppose you had a 20-A circuit in your home or apartment that provided electric current at the standard household voltage of 120 V, what is the maximum power that this circuit could provide to a household appliance? → 2400 W
  • An elite athlete can generate what level of power for short periods of time (a sprint event at the Olympics)? → 1-2 kW
  • A metabolic equivalent (MET) is a unit of → power pet unit body mass
  • If an object’s speed increases by a factor of three, its kinetic energy will increases by a factor of → nine
  • What level of electrical shock will cause involuntary muscle spasms in humans? → 10-20 mA
  • Why is it safe to touch a “plasma globe” without receiving a serve electrical shock? → The plasma streamers are at high voltage but low current.
  • A particular advantage of alternating current (AC) over direct current (DC) is that → AC can be more efficiently distributed over the grid at high voltages. and AC voltages can be easily changed by using transformers.
  • The campus radio station KLSU broadcasts at 91.1 MHz on the FM dial. What is the approximate wavelength of these radio waves? → 3.3m
  • “Talk radio” WJBO broadcasts at 1150 kHz on the AM dial. What is the approximate wavelength of these radio waves? → 260m
  • What do you call a room that is completely shielded from external electric and magnetic fields (for example, a room designed for top-secret communications, safe from eavesdroppers)? → Faraday Cage
  • Chose the correct sequence of electromagnetic radiation, in order of increasing wavelength. → UV, visible, IR, radio
  • Which of the following statements regarding radio waves and X-rays are true? → X-rays have higher frequencies, compared to radio waves and Radio waves have longer wavelengths, compared to X-rays.
  • A standard kitchen microwave oven heats food by generating microwaves at a frequency of 2.45 GHz. What is the approximate wavelength of these radio waves? → 12 cm
  • Radio waves and X-rays have the → same speed
  • A black light is designed to emit → UV light
  • Healthy humans maintain a constant body temperature of approximately 98 degrees Fahrenheit. Any object at this temperature primarily emits → IR light
  • An electron-Volt (eV) is a unit of → energy
  • A photon is → a “massless” particle of light that contains pure energy.
  • In physics a “blackbody” is an idealized object that → Both emits and absorbs light in a manner determined by its temperature.
  • A glowing blackbody at a particular temperature produces what kind of spectrum? → a continuous spectrum
  • For an electron to jump from a lower orbit to a higher orbit in an atom, it must → Absorb a photon of light that has an energy exactly equal to the energy difference between the two orbits
  • What is the physical significance of Planck’s constant, h? → It is a fundamental constant of Nature that is related to the quantum of energy. Its existence was postulated by Planck to explain the observed characteristics of blackbody radiation. It was incorporated by Einstein into his explanation of the puzzling photoelectric effect (for which he won the Nobel prize). It was incorporated by Bohr into his planetary model of atom to describe the quantized nature of the angular momentum of an electron in an atomic orbit