Action and use of circuit components

Formula: V = IR
Calculation: V = 0.5 A * 10 ohms = 5 V
Answer: The potential difference across the resistor is 5 V. Explanation: Ohm's Law states that voltage is directly proportional to the product of current and resistance.

The potential difference across the conductor increases. Explanation: According to Ohm's Law (V=IR), if the resistance (R) increases while the current (I) remains constant, the potential difference (V) must also increase to maintain the equality.

V = IR. First calculate the total resistance: R_total = 200Ω + 300Ω = 500Ω. Then calculate the current: I = V/R = 12V / 500Ω = 0.024A. Finally, calculate the voltage across the 200Ω resistor: V = IR = 0.024A * 200Ω = 4.8V. The voltage across the 200Ω resistor is 4.8V.

A variable potential divider uses a variable resistor to split the voltage from a power supply. By adjusting the position of the sliding contact on the variable resistor, the proportion of the total resistance across which the lamp is connected changes. This alters the voltage across the lamp. Moving the slider towards one end of the resistor increases the voltage across that section, thus increasing the voltage supplied to the lamp. Moving the slider towards the other end decreases the voltage across the lamp.

Formula: V₁ = (R₁ / (R₁ + R₂)) * V_in

Calculation: V₁ = (300 / (300 + 500)) * 12V = (300/800) * 12V = 0.375 * 12V = 4.5V

Answer: The voltage across the 300 Ω resistor is 4.5V. This is because the voltage divides proportionally to the resistance.

A potential divider uses resistors in series to 'divide' the input voltage. The voltage across each resistor is proportional to its resistance. The higher the resistance of a resistor compared to the total resistance, the greater the proportion of the input voltage that will appear across it. Therefore, by using a resistor network, the voltage across a single resistor will always be lower than the total supply voltage unless that resistor comprises the whole resistance in the circuit.