Physics

• What is the unit of current?

  Amperes, A
• How is current defined?

  Rate of flow of electrical charge
• How many coulombs are in 1 ampere per second?

  1 coulomb
• What is the unit of potential difference?

  Volts, V
• What does potential difference measure?

  Work done per unit of charge
• What is the relationship of joules to volts and coulombs?

  1 volt = 1 joule per coulomb
• What is the unit of resistance?

  Ohms, Ω
• What does resistance measure?

  Difficulty of current flow through a component
• What is the unit of power?

  Watts, W
• How is power defined?

  Rate at which energy is transferred
• How many joules are in 1 watt per second?

  1 joule
• What does Ohm's law state?

  Current is proportional to potential difference
• What is the formula for Ohm's law?

  I = V/R
• What are the characteristics of a series circuit?

  • Only one route for current
  • Current is the same throughout
  • Total resistance is the sum of individual resistances
• What are the characteristics of a parallel circuit?

  • Multiple routes for current
  • Voltage is the same across all branches
  • Total resistance is less than the smallest branch resistance
• What is alternating potential difference?

  Potential difference alternates between positive and negative
• What is direct potential difference?

  Potential difference has a constant value
• What is an LDR?

  Light dependent resistor
• How does an LDR function?

  Resistance depends on light intensity
• What is a thermistor?

  A resistor that depends on temperature
• How does a thermistor behave with temperature changes?

  Higher temperature leads to lower resistance
• What are the functions of transformers?

  • Step-up transformer: Increases potential difference, reduces current
  • Step-down transformer: Decreases potential difference, increases current
• What is the formula for power in terms of current and potential difference?

  P = IV
• What is the formula for energy transferred?

  E = Pt
• What is the formula for charge?

  Q = It
• What is the formula for resistance?

  R = V/I
• What is the formula for voltage?

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

  P = I^2R
• What is the formula for power in terms of voltage and resistance?

  P = V^2/R
• What is the formula for energy in terms of voltage and charge?

  E = QV
• What is the formula for energy in terms of current and time?

  E = ItV
• What is the formula for energy in terms of power and time?

  E = Pt
• What is the formula for current in terms of charge and time?

  I = Q/t
• What is the formula for voltage in terms of energy and charge?

  V = E/Q
• What is the formula for resistance in terms of voltage and power?

  R = V^2/P
• What is the formula for power in terms of current and resistance?

  P = I^2R
• What is the formula for power in terms of voltage and current?

  P = IV
• What is the formula for charge in terms of current and time?

  Q = It
• What is the formula for resistance in terms of voltage and current?

  R = V/I