PHYS165 / PHYS 165 Module 8: (Latest Update 2026 / 2027) Physics | Questions, Answers and Review Material | Portage Learning 2026 / 2027 Academic Year

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PHYS165 / PHYS 165 Module 8: (Latest Update 2026 / 2027) Physics | Questions, Answers & Review Material | Grade A | 100% Correct - Portage Learning ... 2026 / 2027 Academic Year Q: What is the relationship between the cross-sectional area of a wire and its resistance? Answer: Inverse Propotion Q: True or False: Direct current reverses direction at regular intervals. Answer: a) The current through each resistor is the same b) The equivalent resistance is equal to the sum of the individual resistances c) The total voltage across the circuit is equal to the sum of the individual voltages False The electrons will move in a counterclockwise path around the circuit and only one direction inside of the wire. Positive to Negative Q: For a collection of resistors that are connected in series, which of the following statements is true? Assume that the resistance of each resistor is different. a) The current through each resistor is the same b) The equivalent resistance is equal to the sum of the individual resistances c) The total voltage across the circuit is equal to the sum of the individual voltages d) All of the above are true Answer: d) All of the above are true Q: True or False: Kirchhoff's Loop Rule states that the sum of the potential differences around any closed loop in an electric circuit is always greater than the current in the circuit. Answer: False. Kirchhoff's Loop Rule states that the sum of the electric potential differences (voltages) around any closed loop is zero. Q: For a collection of resistors that are connected in parallel, which of the following statements is true? Assume that the resistance of each resistor is different. A) The sum of the current through each resistor is equal to the total current of the circuit. B) The equivalent resistance is equal to the sum of the individual resistances. C) The total voltage of the circuit is equal to the sum of the voltages across each resistor. D) A, B, and C are true. Answer: A) The sum of the current through each resistor is equal to the total current of the circuit. current - changes voltage- same more branches = increased current decreased resistance Q: True or False: Kirchhoff's Junction Rule states that the sum of the current entering a junction must equal the sum of the current exiting a junction. Answer: True That the total current into a junction equals the total current out of the junction. What goes in must come out Q: The circuit in Figure 8.T.5 contains two batteries and one resistor connected in series. At which point is the current the largest? Answer: 2 Batteries in Series w/ Resistor Parallel The current is the same at all of the points Q: The circuit in Figure 8.T.5 contains two batteries and one resistor connected in series. At which point is the electric potential energy of the charges the largest? Answer: 2 Batteries in Series w/ Resistor Parallel Point C--- points before the resistor Q: Which of the following equations correctly applies Kirchhoff's Junction rule to the figure below? Current flows and splits into two and combines again A) I 3 = I 4 B) I 2 = I 3 C) I 1 + I 2 = 1 3 + 1 4 D) 1 2 + I 3 = I 4 Answer: D) 1 2 + I 3 = I 4 Q: True or False: Complex circuits can be broken down into combinations of series and parallel circuits. Answer: True Series- all components are connected end-to-end to form a single path for current flow. The total resistance in a series circuit is equal to the sum of the individual resistors, and the total voltage drop is equal to the sum of the individual voltage drops across those resistors. Parallel - all components are connected across each other, forming exactly two sets of electrically common points. A "branch" in a parallel circuit is a path for electric current formed by one of the load components (such as a resistor). Q: A 6.0-volt battery is connected in a circuit with a 4.0-ohm resistor. Find the current through the circuit. Show your work. Answer: V= 6 R= 4 Use ΔV = IR I= V/R I= 6.0/ 4.0 I= 1.5 amps Q: A 20-Ω and 10-Ω resistor are wired in series. Calculate the equivalent resistance. Answer: Use Rt= R1+R2 Rt= 20 + 10 = 30 30 Ohms Q: A 5.00-Ω and 11.0-Ω resistor are wired in parallel. Calculate the equivalent resistance. Answer: (1/R)=(1/R1)+(1/R2) So(1/R)=(1/5.00)+(1/11.0) 1/.29 for RT 3.45 ohms Q: What is the resistivity of a wire that is 5.25 m long, has a cross-sectional area of 4.24 x 10-5 m2, and a resistance of 0.196 ? Answer: p=RA/I p= (0.196) x (4.24 x 10^5) / (5.25) p = 1.5829 p = 1.58 Ωm A) 1/Rt= 1/R1+1/R2 1/Rt= 1/ 95 + 1/35 = 2.56 2.56 Ohms Q: What is the maximum value of AC current when the effective value of current is 8.42 A? Answer: Imax= (Sqaure root 2)(Ieff) Imax= (8.42) x √2 Imax= 11.907 11.9 Amps Q: Figure 8.T.2 shows a portion of a circuit that contains four resistors with resistance as shown in the figure. Calculate the following values: A. Calculate the equivalent resistance of the 95- and 35- resistors. B. Calculate the equivalent resistance of the 25-, 95-, and 35- resistors. C. Calculate the equivalent resistance of the entire circuit. Answer: B) Rt= R1+R2 2.56 + 25 = 27.56 Ohms C) 1/Rt= 1/R1 + 1/R2 1/x for Rt. Answer in Ohms Q: An electronic device uses a circuit with a 20.0-ohm resistor. If the current through the circuit is 4.00 amps, how much power is used by the device? Answer: P=I^2R Answer in Watts P= 4^2 x 20.0 P = 320 W Q: In a certain town, electricity is sold at a rate of 12.25 cents per kilowatt-hour. A refrigerator uses 725.0 kilowatt-hour of energy in exactly one year, and it is connected to a 121-v outlet. Answer the following questions about this refrigerator. A. What is the cost of operating this refrigerator for one year? B. What is the average power expended on this refrigerator during this year of operation? C. What is the average amount of current drawn by the refrigerator? Answer: A) Cost = (Rate)(Energy) (12.25 cents) x (725 units/year) = 8881.25 cents/ year ($88.81/ year) B) Energy/t with 725kw*h/1year converted down to 24 hours = 82.7W c) I=P/V=82.7 I= 82.76/ 725 I = .114 amps Q: What is the relationship between the cross-sectional area of a wire and its resistance? Answer: Inverse Propotion Q: True or False: Direct current reverses direction at regular intervals. Answer: False Q: For a collection of resistors that are connected in series, which of the following statements is true? Assume that the resistance of each resistor is different. a) The current through each resistor is the same b) The equivalent resistance is equal to the sum of the individual resistances c) The total voltage across the circuit is equal to the sum of the individual voltages d) A,B, and C are true Q: True or False: Kirchhoff's Loop Rule states that the sum of the potential differences around any closed loop in an electric circuit is always greater than the current in the circuit. Answer: False. Kirchhoff's Loop Rule states that the sum of the electric potential differences (voltages) around any closed loop is zero. Q: For a collection of resistors that are connected in parallel, which of the following statements is true? Assume that the resistance of each resistor is different. Answer: The sum of the current through each resistor is equal to the total current of the circuit

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