Electric Potential Difference Quiz

Electric Potential Difference

• Electric potential difference, often called voltage, is the difference in electrical potential energy per unit charge between two points in a circuit.
• It's measured in volts (V).
• A volt is defined as one joule of energy per coulomb of charge.
• Voltage is analogous to the elevation difference between two points.
• Voltage is necessary to maintain current flow within a circuit.

Relation between Potential Difference and Work

• The work done to move a charge between two points is directly proportional to the magnitude of the charge and the potential difference between the points.
• Work (W) = charge (Q) × potential difference (V).

Equipotential Lines

• Equipotential lines are imaginary lines connecting points having the same electric potential.
• Points along an equipotential line have no potential difference between them.
• Work is zero when moving a charge along an equipotential line.
• Equipotential lines are always perpendicular to the electric field lines.

Battery Voltage

• A battery is a source of electrical potential difference.
• The terminals of a battery are maintained at a specific potential difference.
• The voltage of the battery is the potential difference between its two terminals.
• A battery does not maintain a constant flow of current directly; it maintains a potential difference.

Voltage and Current

• Voltage provides the "driving force" that pushes charges through a circuit—like a water pump creating pressure for water to flow.
• Current is the rate of flow of charge through the circuit, measured in amperes (A).
• Ohm's Law (V = IR) relates voltage, current, and resistance in a circuit. A higher voltage across a given resistance will result in a higher current.

Potential Difference and Energy

• Electrical potential energy stored in a charge is dependent on the charge's magnitude and its position within the circuit. This potential energy is converted to heat and light when the charge flows through the circuit.
• Voltage provides the energy source for electric current to flow.

Calculating Potential Difference

• The potential difference of a circuit component can be derived with known values of current and resistance through the use of Ohm's law.

Voltage across a Resistor

• If resistance in a circuit increases, potential difference increases for a given current, according to the relationship established in Ohm's Law.
• If current in a circuit increases, potential difference increases for a given resistance, according to the relationship established in Ohm's Law.

Significance of Potential Difference

• Potential difference is essential to have current flow in an electrical circuit.
• Potential difference is directly related to the energy required to move charges within a circuit.
• It's an element vital for calculating the amount of power delivered in a circuit, and crucial for circuit design across various applications.