electricity

• What is voltage or potential difference defined as?

  Work done in moving 1C of charge
• What does EMF stand for?

  Electromotive force
• What does EMF represent in a battery?

  Total work done by a battery
• How is current defined?

  Charge flow per second
• What is a superconductor?

  Has a resistance of 0 at critical temperature
• What is the critical temperature?

  Temperature at or below which resistance is 0
• What does internal resistance refer to?

  Resistance of materials in a battery
• What are the characteristics of IV curves for resistors and superconductors?

  • Resistor: Linear relationship between V and I
  • Superconductor: R = 0 below Tc
• What happens to current as voltage increases in a superconductor?

  Current increases as voltage increases
• What is the effect of power on a conductor?

  Power heats up the conductor
• What happens to energy collisions as current increases?

  Less energy is lost in collisions
• What is the forward bias voltage for a standard diode?

  0.7V
• What occurs in reverse bias for a diode?

  Resistance is very high, negligible current
• What happens at -50V for a diode?

  Resistance is low, current is high
• What is the forward bias voltage for an LED?

  2.2V
• What is the behavior of a light-dependent resistor (LDR) as light increases?

  • Resistance decreases as light increases
• What is the behavior of a thermistor as temperature increases?

  • Resistance decreases as temperature increases
• What is the formula for Ohm's Law?

  V = IR
• What is the formula for power in terms of current and voltage?

  P = IV
• What is the formula for power in terms of resistance?

  P = I²R
• What is the formula for power in terms of voltage and resistance?

  P = V²/R
• What are the rules for series circuits?

  • R₁ = R₁ + R₂
  • V₁ = V₂ = V₃
  • Current is the same (A₁ = A₂ = A₃)
• What are the rules for parallel circuits?

  • 1/R₁ = 1/R₂ + 1/R₃
  • V₁ = V₂ = V₃
  • Current adds up (A₁ = A₂ + A₃)
• How does the resistance in a series circuit compare to a parallel circuit?

  Resistance adds up in series, decreases in parallel
• How does voltage behave in series circuits compared to parallel circuits?

  Voltage adds up in series, is the same in parallel
• How does current behave in series circuits compared to parallel circuits?

  Current is the same in series, adds up in parallel