5.1 Current electricity

• Electron flow is the actual movement of electrons
• Conventional current flows from the positive to the negative terminal.
• Resistance is measured in ohms.


  True
• Variable resistors can be adjusted to change their resistance.


  True
• Conventional current flows from the positive to the negative terminal in a circuit.

  True
• What is electric current defined as?

  Flow of electric charge
• Match the type of flow with its direction:

  Conventional Current ↔️ Positive to negative

  Electron Flow ↔️ Negative to positive
• Match the type of resistor with its example:

  Fixed Resistor ↔️ Carbon film

  Variable Resistor ↔️ Potentiometer

  Special Purpose Resistor ↔️ Thermistor
• What is a circuit defined as?

  A closed path for current
• The total resistance in a parallel circuit is calculated using the formula $1 / R_\text{total} =$$1 / R_{1} +$$1 / R_{2} +$$... +$$1 / R_{n}$, where resistance is the constant of proportionality.
• The total resistance in a parallel circuit with a 10 Ω resistor and a 20 Ω resistor is 6.67 Ω
• Match the circuit type with the correct current calculation:

  Series circuit ↔️ $I_\text{total} =$$V_\text{total} / R_\text{total}$

  Parallel circuit ↔️ $I_\text{total} =$$I_{1} +$$I_{2} +$$... +$$I_{n}$
• Electron flow occurs from the negative terminal to the positive terminal, opposite to the direction of conventional current.
• If a resistor has a resistance of 10 Ω and a current of 2 A, the voltage across it is 20 V.


  True
• Voltage measures the electric potential difference across a conductor.


  True
• What does the power rating of a resistor indicate?

  Maximum power it can dissipate
• What is the key characteristic of current in a series circuit?

  Same through all components
• What is the formula for electrical energy in joules?

  $E =$$VIt$
• Electrical energy is measured in watts

  False
• A device with a resistance of 50 ohms connected to a 120V source consumes 288 watts of power.

  True
• What does Kirchhoff's Current Law (KCL) state?

  Sum of currents entering a node equals the sum of currents leaving
• What is the equation for KVL in a closed loop?

  $\sum V_{drops} =$$0$
• When applying KVL, you must assign directions to the currents and voltage drops.


  True
• Which law is used to find voltage, current, or resistance in a simplified circuit?

  Ohm's Law
• Conventional current is the flow of positive charge.


  True
• What type of charge carriers are present in most conductors?

  Electrons
• The formula for Ohm's Law is V = IR
• Fixed resistors have a constant resistance value
• The power rating of a resistor is the maximum power it can safely dissipate
• Electric current is the flow of electric charge
• Electron flow occurs in the same direction as conventional current.

  False
• According to Ohm's Law, voltage is directly proportional to current if temperature remains constant
• Fixed resistors have a constant resistance value.

  True
• What is tolerance in resistors?

  Allowed variation in resistance
• What is the total resistance in a series circuit?

  Sum of individual resistances
• What happens to the current in a series circuit?

  Same current through each component
• What is the primary difference between a series and a parallel circuit in terms of voltage?

  Series: voltage drops add up ||| Parallel: same voltage across all components
• In a series circuit, the current path is single
• The direction of conventional current is the flow of positive charge.

  True
• Match the variable with its unit and description:

  Voltage ↔️ Volts (V) ||| Electric potential difference across a conductor

  Current ↔️ Amperes (A) ||| Rate of flow of electric charge

  Resistance ↔️ Ohms ($\Omega$) ||| Opposition to the flow of current