Question 1: Define potential difference in the context of an electric circuit.

Answer: Potential difference is the work done per unit charge to move a charge between two points in a circuit, measured in volts.

Question 2: Explain how potential difference relates to the energy transferred in a circuit.

Answer: Potential difference indicates the energy transferred per unit charge as it moves through a component, so a higher PD means more energy transfer for each coulomb of charge.

Question 3: Describe the mechanism by which potential difference drives current through a resistor.

Answer: A voltage across the resistor creates an electric field that exerts a force on charges, causing them to move and produce current, with energy being dissipated as heat.

Question 1: A circuit has a current of 2 A flowing through a resistor. If the resistor dissipates 12 W of power, calculate the potential difference across the resistor. (Use P = V × I)

Answer: V = P / I = 12 W / 2 A = 6 volts

Question 2: A battery supplies a potential difference of 9 V. If a current of 3 A flows in the circuit, what is the total resistance? (Use R = V / I)

Answer: R = V / I = 9 V / 3 A = 3 ohms

Question 1: Describe a safe method to measure the potential difference across a component in a circuit using a voltmeter.

Answer: Connect the voltmeter in parallel across the component, ensuring the circuit is powered off before connecting, then turn on the circuit and read the voltage from the meter.

Question 2: Identify the variables that could affect the accuracy of PD measurements in an experimental setup.

Answer: Variables include the internal resistance of the voltmeter, contact resistance at connections, and fluctuations in the circuit power supply.

Question 1: A circuit with a fixed current of 2 A has a potential difference of 10 V across one resistor and 5 V across another. Explain what this indicates about the resistances of these components.

Answer: The resistor with 10 V has a higher resistance than the one with 5 V, assuming the current is the same, since V = IR.

Question 2: In a series circuit, if the total PD supplied by the power source is 12 V, and three resistors share the voltage with 4 V, 4 V, and 4 V respectively, what does this tell you about the resistances of the resistors?

Answer: All three resistors have equal resistance, since they each have the same voltage drop in a series circuit with equal current.

Question 1: Explain how potential difference affects the energy transferred in an electrical component, and illustrate your answer with an example involving a light bulb.

Answer: Potential difference determines the amount of energy transferred per unit charge as it passes through a component. For example, in a light bulb connected to a 12 V supply, each coulomb of charge gains 12 joules of energy, which is then converted into light and heat.

Question 2: A student measures the potential difference across a resistor in a circuit and finds it to be higher than expected. List possible reasons for this discrepancy and how it could be investigated.

Answer: Possible reasons include a faulty or internal resistance in the voltmeter, loose connections, or an overvoltage supply. Investigation involves checking connections, using a different voltmeter, and verifying the power supply voltage.

Question 1: Explain how potential difference is crucial in the operation of electric vehicles (EVs), and what safety considerations are involved.

Answer: In EVs, the battery's potential difference provides the energy to drive the motor. Safety considerations include ensuring proper insulation, protective circuitry to prevent overvoltage, and correct handling of high-voltage systems.

Question 2: Identify a modern technological device that relies heavily on potential difference for its operation and briefly describe its functioning related to PD.

Answer: Solar panels rely on potential difference generated by the photovoltaic effect, where sunlight creates a voltage across the semiconductor, enabling current flow for electricity generation.