Post

Created by @nathanedwards
 at October 31st 2023, 3:51:33 pm.

AP Physics 1 Exam Question:

A 5-ohm resistor is connected in series with a 12-ohm resistor and a power supply. The power supply provides a constant potential difference of 24 volts. Calculate:

a) The total resistance of the circuit. b) The current flowing through the circuit. c) The power dissipated by each resistor.

Assume all resistors have negligible internal resistance.

Solution:

a) The total resistance of a series circuit is the sum of the individual resistances. Therefore, the total resistance (R_total) can be calculated as:

R_total = R1 + R2

Given that R1 = 5 ohms and R2 = 12 ohms, we can substitute these values into the equation to find R_total:

R_total = 5 ohms + 12 ohms R_total = 17 ohms

Therefore, the total resistance of the circuit is 17 ohms.

b) The current (I) flowing through a circuit can be calculated using Ohm's Law, which states that the current is equal to the potential difference (V) across the circuit divided by the total resistance (R_total). Mathematically, this can be represented as:

I = V / R_total

Given that V = 24 volts and R_total = 17 ohms, we can substitute these values into the equation to find I:

I = 24 volts / 17 ohms I ≈ 1.41 amperes (rounded to two decimal places)

Therefore, the current flowing through the circuit is approximately 1.41 amperes.

c) The power dissipated by a resistor (P) can be calculated using the formula:

P = I^2 * R

where I is the current flowing through the resistor and R is the resistance of the resistor. Let's calculate the power dissipated by each resistor:

For the 5-ohm resistor: P1 = I^2 * R1 P1 = (1.41 amperes)^2 * 5 ohms P1 ≈ 9.95 watts (rounded to two decimal places)

For the 12-ohm resistor: P2 = I^2 * R2 P2 = (1.41 amperes)^2 * 12 ohms P2 ≈ 23.62 watts (rounded to two decimal places)

Therefore, the power dissipated by the 5-ohm resistor is approximately 9.95 watts, and the power dissipated by the 12-ohm resistor is approximately 23.62 watts.