Module 6 Electric Current and DC Сircuits

HW: Module 6 Electric Current and DC circuits Problem 1: A voltmeter is connected to the parallel-plate capacitor shown in the figure. Answer the following questions concerning the impact of specified changes upon the capacitance. - Part (a) If the gap between the plates is increased, then the capacitance Correct Answer Student Final Submission Feedback will decrease. will decrease. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 16, 2022 8:16 PM will increase. -Capacitance is impacted by geometry and dielectric properties. For a parallel-plate capacitor we have a formula for the capacitance. Note: Feedback not accessed. 2 Feb 16, 2022 8:16 PM will decrease. Part (b) If the area of the plates is increased, then the capacitance Correct Answer Student Final Submission Feedback will increase. will increase. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 16, 2022 8:17 PM will decrease. -Capacitance is impacted by geometry and dielectric properties. For a parallel-plate capacitor we have a formula for the capacitance. Note: Feedback not accessed. 2 Feb 16, 2022 8:17 PM will increase. Part (c) If the voltage indicated on the voltmeter increases without changes to either the conductors or the dielectric materials, then the capacitance Correct Answer Student Final Submission Feedback remains unchanged. remains unchanged. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] 0% Student Grade = 100 - 0 - 0 = 100% Date Time Answer Hints 1 Feb 16, 2022 8:17 PM 2 Feb 16, 2022 8:17 PM accessed. 3 Feb 16, 2022 8:17 PM with the information provided. 4 Feb 16, 2022 8:17 PM Feedback increases. decreases. Note: Feedback not accessed. Note: Feedback not may change, but we cannot determine how it will change Note: Feedback not accessed. remains unchanged. Part (d) If the charge stored on the plates is increased, then the capacitance Correct Answer Student Final Submission Feedback remains unchanged. remains unchanged. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] 0% Student Grade = 100 - 0 - 0 = 100% Date Time Answer Hints 1 Feb 16, 2022 8:18 PM accessed. 2 Feb 16, 2022 8:18 PM 3 Feb 16, 2022 8:18 PM Feedback decreases. Note: Feedback not increases. Note: Feedback not accessed. remains unchanged. Part (e) If the air in the gap is replaced with glass, then the capacitance Correct Answer Student Final Submission Feedback increases. increases. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 Time Answer Hints Feb 16, 2022 8:18 PM 0% Feedback increases. Problem 2: Three capacitors are connected as shown, where C = 0.055 F. - Part (a) What is the equivalent capacitance, in farads, between points A and B? Grade = 0% Correct Answer Student Final Submission Ceq = 0.1375 Ceq = 2.5 Feedback Grade Summary Deduction for Final Submission 100% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 100 - 0 = 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 4:38 PM Ceq = 0.275 correct. We have recognized the following, - Your answer appears to be off by a factor of 2. 2 Feb 17, 2022 4:38 PM Ceq = 0.55 3 Feb 17, 2022 4:38 PM Ceq = 0.475 4 Feb 17, 2022 4:40 PM Ceq = 0.25 5 Feb 17, 2022 5:55 PM Ceq = 2.5 0% The answer provided was not Part (b) If the capacitors are charged with a ΔV = 10 V source, how much energy will the circuit store, in joules? Correct Answer Student Final Submission Feedback E = 6.875 E = 6.875 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:57 PM E = 0.6875 -Use the expression for the energy stored in a capacitor in terms of its capacitance and voltage. You may have forgotten to square voltage. 2 Feb 17, 2022 5:57 PM E = 6.875 Problem 3: A charge of Q = 1.9 C passes through a wire every t = 9.5 s. Part (a) What is the current in amperes? Correct Answer Student Final Submission Feedback I = 0.2 I = 0.2 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 2 3 Time Answer Hints Feedback Feb 17, 2022 4:22 PM I = 18.05 Feb 17, 2022 4:22 PM I = 12 Feb 17, 2022 4:27 PM I = 0.2 0% -Use the definition of current. Part (b) What is the current, in milliamps? Correct Answer Student Final Submission Feedback I = 200 I = 200 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 Time Answer Hints Feedback Feb 17, 2022 4:30 PM I = 200 0% Problem 4: The 195 A current through a spark plug moves 0.475 mC of charge. How long does the spark last, in microseconds? Correct Answer Student Final Submission Feedback Δt = 2.436 Δt = 2.435 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 4:45 PM Δt = 2.44 * 10( - 6 ) Δt = 2.44E-6 -How is the current related to the charge and time is takes to move the charges? The answer provided was not correct. We have recognized the following, - Your answer appears to be off by a factor of 10n, where n is an integer value. Ensure you have represented the number in the correct units. 2 Feb 17, 2022 4:47 PM Δt = 2.44 * 10( - 3 ) Δt = 0.00244 You may have forgotten to convert your variables and final answer into the proper units. 3 Feb 17, 2022 4:51 PM Δt = 2.4 * 10( 6 ) Δt = 2400000 The answer provided was not correct. We have recognized the following, - Your answer appears to be off by a factor of 10n, where n is an integer value. Ensure you have represented the number in the correct units. 4 Feb 17, 2022 4:52 PM Δt = 2.435 Problem 5: A current of I = 7.3 A is passing through a conductor with cross sectional area A = 6.5 × 10-4 m2. The charge carriers in the conductor, electrons, have a number density n = 2.1 x 1027 m-3. - Calculate the numerical value of the drift velocity, v, in m/s. Correct Answer Student Final Submission Feedback vd = 3.342E-5 vd = 3.35 * 10( - 5 ) vd = 3.35E-5 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 4:54 PM vd = 0.123 2 Feb 17, 2022 4:54 PM vd = 0.923 3 Feb 17, 2022 5:38 PM vd = 3.35 * 10( - 6 ) vd = 3.35E-6 The answer provided was not correct. We have recognized the following, - Your answer appears to be off by a factor of 10n, where n is an integer value. Ensure you have represented the number in the correct units. 4 Feb 17, 2022 5:38 PM vd = 3.35 * 10( - 5 ) vd = 3.35E-5 Problem 6: The figures below demonstrate four current-voltage characteristics of different resistors. - Which of them demonstrates Ohmic behavior? Grade = 25% Correct Answer Student Final Submission Feedback 4 3 In figure 3, every value of current can be found for a given value of potential. What happens if we pick a different value for potential? If this was true, we could never predict the current through a resistor based on applied voltage! Grade Summary Deduction for Final Submission 75% Deductions for Incorrect Submissions, Hints and Feedback [?] 0% Student Grade = 100 - 75 - 0 = 25% Date Time Answer Hints Feedback 1 Feb 17, 2022 4:14 PM 1 and 4 -Ohmic behavior means the resistor obeys Ohm's law. In an ohmic resistor, what current should be found for a very small potential? Does an ideal resistor have a minimal potential requirement in order to produce a current? 2 Feb 17, 2022 4:14 PM 1, 2, 4 Note: Feedback not accessed. 3 Feb 17, 2022 4:14 PM 1 and 2 Note: Feedback not accessed. 4 Feb 17, 2022 4:14 PM 2 and 4 In an ohmic resistor, what current should be found for a very small potential? Does an ideal resistor have a minimal potential requirement in order to produce a current? 5 Feb 17, 2022 4:15 PM 3 Note: Feedback not accessed. Problem 7: Suppose you have a 3.5 V flashlight. What current, in amperes, flows through the bulb of the flashlight when its resistance is 3.55 Ω? Correct Answer Student Final Submission Feedback I = 0.9859 I = 0.98 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:23 PM I = 12.425 I = 12.43 -What basic equation connects current, voltage, and resistance? -What is current times resistance? -This is a simple application of Ohm's law. Use the Ohm's law and check your algebra. 2 Feb 17, 2022 5:24 PM I = 0.98 Problem 8: Suppose you have a 22 m long piece of copper wire with a 2.268 mm diameter and a resistivity of 1.72 × 10-8 Ω⋅m. What is the resistance of the copper wire, in ohms? Correct Answer Student Final Submission Feedback R = 0.09366 R = 0.093712 R = 0.09371 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:31 PM R = 2.34 * 10( - 4 ) R = 2.34E-4 2 Feb 17, 2022 5:33 PM R = 9.95 * 10( - 4 ) R = 9.95E-4 3 Feb 17, 2022 5:34 PM R = 9.36 * 10( - 8 ) R = 9.36E-8 You may have forgotten to convert diameter into meters. 4 Feb 17, 2022 5:36 PM R = 22 5 Feb 17, 2022 5:49 PM R = 0.093712 R = 0.09371 Problem 9: A defibrillator sends a 6.75 A current through the chest of a patient by applying a 9500 V voltage as in the figure. - What is the resistance of the path in kΩ? Correct Answer Student Final Submission Feedback R = 1.407 R = 1.41 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 0% Time Answer Hints Feedback Feb 17, 2022 5:47 PM R = 1.41 Problem 10: Suppose a 1.25 × 102 MV lightning bolt has a current of 2.2 × 104 A. What is the power, in watts, of such a lightning bolt? Correct Answer Student Final Submission Feedback P = 2.75E+12 P = 2.75 * 10( 12 ) P = 2.75E+12 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 6:00 PM P = 2750000 -Use the expression for power in terms of voltage and current. You may have forgotten to convert voltage into V. 2 Feb 17, 2022 6:02 PM P = 2.75E+12 P = 2.75 * 10( 12 ) Problem 11: Find the power dissipated (in W) in each of the following extension cords: Part (a) An extension cord having a 0.065 Ω resistance and through which 5.00 A is flowing. Correct Answer Student Final Submission Feedback P = 1.625 P = 1.625 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 6:05 PM P = 0.325 -What happens to the power dissipated if the resistance is increased? -You may need to combine two basic equations to find a useful expression. You may have forgotten to square current. 2 Feb 17, 2022 6:05 PM P = 1.625 Part (b) A cheaper cord utilizing thinner wire and with a resistance of 0.36 Ω through which 5.00 A is flowing. Correct Answer Student Final Submission Feedback P = 9 P = 9 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date 1 Time Answer Hints Feedback Feb 17, 2022 6:05 PM P=9 Problem 12: Two unequal resistors are connected as shown. (R1 ≠ R2) - Which statement is most true concerning the current through each resistor and the voltage measured across each resistor? Correct Answer Student Final Submission Feedback The current is the same through both resistors, but the voltage across each resistor is different. The current is the same through both resistors, but the voltage across each resistor is different. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] 0% Student Grade = 100 - 0 - 0 = 100% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:42 PM The current is the same through both resistors, but the voltage across each resistor is different. Problem 13: Two unequal resistors are connected as shown. (R1 ≠ R2) - Which statement is most true concerning the current through each resistor and the voltage measured across each resistor? Correct Answer Student Final Submission Feedback The current is different through each resistor, but the voltage across both resistors is the same. The current is different through each resistor, but the voltage across both resistors is the same. Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] 0% Student Grade = 100 - 0 - 0 = 100% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:28 PM The current is the same through both resistors, but the voltage across each resistor is different. Note: Feedback not accessed. 2 Feb 17, 2022 5:28 PM The current is the same through both resistors, and so is the voltage across both resistors. Note: Feedback not accessed. 3 Feb 17, 2022 5:28 PM The current is different through each resistor, but the voltage across both resistors is the same. Problem 14: Consider connecting three resistors of resistances 31 Ω, 55 Ω, and 715 Ω together. Part (a) What is the largest resistance you can obtain in Ω? Correct Answer Student Final Submission Feedback Rl = 801 Rl = 801 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:26 PM Rl = 801 -Does connecting the resistors in series or parallel result in a larger resistance? -What about connecting some in parallel and some in series; could that result in a larger resistance than just in parallel or series? -When in series, each resistor "blocks the entire current", while in parallel they each block only part of the current. Part (b) What is the smallest resistance you can obtain in Ω? Correct Answer Student Final Submission Feedback Rs = 19.29 Rs = 19.29 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:27 PM Rs = 0.052 resistance in parallel. 2 Feb 17, 2022 5:27 PM Rs = 19.29 0% This is the reciprocal to the Problem 15: In the circuit diagram R1 = 5R and R2 = 15R, where R = 14 Ω. The power dissipated in resistor 2 is P = 1.6 W. - Part (a) What is the voltage across the battery in volts? Correct Answer Student Final Submission Feedback V = 24.44 V = 24 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 0% Time Answer Hints Feedback Feb 17, 2022 5:48 PM V = 24 Part (b) How much power, Ps, is the source supplying, in watts? Correct Answer Student Final Submission Feedback Ps = 2.133 Ps = 2.1 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 0% Time Answer Hints Feedback Feb 17, 2022 5:48 PM Ps = 2.1 Problem 16: Consider the three resistors R1 = 17 Ω, R2 = 41 Ω, and R3 = 71 Ω in the configuration shown in the figure. A potential difference ΔV = 4.5 V is applied between A and B. - Part (a) Calculate the numerical value of the total resistance R of this circuit, in ohms. Correct Answer Student Final Submission Feedback R = 42.99 R = 43 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 0% Time Answer Hints Feedback Feb 17, 2022 5:39 PM R = 43 Part (b) Calculate the numerical value of the current I traveling from A to B, in amperes. Correct Answer Student Final Submission Feedback I = 0.1047 I = 0.10467 I = 0.1047 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% 0% Date Time Answer Hints Feedback 1 Feb 17, 2022 5:40 PM I = 9.41 Note: Feedback not accessed. 2 Feb 17, 2022 5:40 PM I = 10467 I = 10470 The answer provided was not correct. We have recognized the following, - Your answer appears to be off by a factor of 10n, where n is an integer value. Ensure you have represented the number in the correct units. 3 Feb 17, 2022 5:40 PM I = 0.10467 I = 0.1047 Part (c) Calculate the numerical value of I2 traveling through the resistor R2, in amperes. Correct Answer Student Final Submission Feedback I2 = 0.06636 I2 = 0.06635 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 2 0% Time Answer Hints Feedback Feb 17, 2022 5:41 PM I2 = 0.00635 Feb 17, 2022 5:42 PM I2 = 0.06635 Part (d) Calculate the numerical value of I3 traveling through the resistor R3, in amperes. Correct Answer Student Final Submission Feedback I3 = 0.03832 I3 = 0.0383 Correct! Grade Summary Deduction for Final Submission 0% Deductions for Incorrect Submissions, Hints and Feedback [?] Student Grade = 100 - 0 - 0 = 100% Date 1 Time Answer Hints Feedback Feb 17, 2022 5:42 PM I3 = 0.0383 0%