5.1 Current electricity

• Electric charge is measured in volts.

  False
• The rate of flow of electric charge is called electric current
• Electric charge is a fundamental property of matter that causes objects to attract or repel each other.


  True
• The mathematical relationship between charge, current, and time is expressed as I = \frac{Q}{t}</latex>
• The equation relating voltage, work done, and charge is $V =$$\frac{W}{Q}$
• What is voltage measured in?

  Volts (V)
• The symbol for voltage is V

  True
• What is the equation for voltage in terms of work and charge?

  $V =$$\frac{W}{Q}$
• In the voltage equation, W stands for work done


  True
• Match the quantity with its definition:

  Voltage ↔️ Potential difference between two points

  Current ↔️ Rate of flow of electric charge

  Resistance ↔️ Opposition to current flow
• One key application of Ohm's law is calculating voltage, current, or resistance
• What is the unit of resistance?

  Ohm (Ω)
• Match the factor with its relationship to resistance:

  Material ↔️ Determines inherent resistance

  Cross-sectional area ↔️ Inversely proportional

  Length ↔️ Directly proportional
• Resistance is inversely proportional to the cross-sectional area
• In a parallel circuit, the voltage is the same across each component


  True
• In a series circuit with R1 = 4Ω and R2 = 2Ω, the total resistance is 6Ω
• In metallic conductors, electrons are the main charge carriers

  True
• Electric current is the rate of flow of electric charge
• Electric current is the rate at which electric charge flows.
• What is the unit of electric charge?

  Coulomb
• One ampere is equivalent to one coulomb per second.


  True
• Match the quantity with its unit and symbol:

  Electric current ↔️ Ampere (A), I

  Electric charge ↔️ Coulomb (C), Q

  Time ↔️ Seconds (s), t
• Voltage is the electrical potential difference between two points.
• Voltage is calculated using the formula V = W/Q, where W is work done and Q is charge.

  True
• Match the quantity with its unit and symbol:

  Voltage ↔️ Volt (V), V

  Current ↔️ Ampere (A), I

  Resistance ↔️ Ohm (Ω), R
• The formula for resistance is R = ρL/A.
• How is total resistance calculated in a parallel circuit?

  $1 / R =$$1 / R_{1} +$$1 / R_{2} +$$...$
• Ohm's law states that the voltage (V) across a conductor is directly proportional to the current
• In a series circuit, the total resistance is the sum of the individual resistances
• The same current flows through all components in a series circuit.


  True
• What is the formula for total resistance in a parallel circuit?

  $\frac{1}{R_\text{total}} =$$\frac{1}{R_{1}} +$$\frac{1}{R_{2}} +$$\dots$
• Steps to analyze a circuit diagram using Ohm's law and series/parallel concepts

  1️⃣ Identify the circuit type (series or parallel)

  2️⃣ Calculate the total resistance

  3️⃣ Apply Ohm's law to find voltage, current, or resistance
• The mathematical formula for Kirchhoff's Voltage Law is $\sum V =$$0$


  True
• How many terminals does a potentiometer have?

  Three
• In a 12V circuit with a potentiometer, what is the voltage if the wiper is at the halfway point?

  6V
• The formula for electrical energy is $E =$$VIt$


  True
• Current electricity is the flow of charge carriers through a conductor
• What is the formula for current?

  $I =$$\frac{Q}{t}$
• What is current electricity defined as?

  Flow of charge carriers
• What are the main charge carriers in metallic conductors?

  Electrons