With the switch in the circuit of Figure 27.4a closed, there is no current in R2 because the current has an alternate zero-resistance path through the switch. There is current in R1, and this current is measured with the ammeter (a device for measuring current) at the bottom of the circuit. If the switch is opened (Fig. 27.4b), there is current in R2. What happens to the reading on the ammeter when the switch is opened? (a) The reading goes up. (b) The reading goes down. (c) The reading does not change.
Figure 27.4 (Quick Quiz 27.2) What happens when the switch is opened?
Trending nowThis is a popular solution!
Chapter 27 Solutions
Physics for Scientists and Engineers with Modern Physics
Additional Science Textbook Solutions
Mathematical Methods in the Physical Sciences
University Physics with Modern Physics (14th Edition)
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
- How do you solve this question? The first question's answer is c) 3.0 T but I can't seem to get the right answer if I attempt use the equation emf = (BA)/t. Is t 1.25, 5, or something else?arrow_forwardAfter being closed for a long time, the switch S in the circuit shown in the figure below is thrown open at t = 0. In the circuit, E= 24.0 V, RA = 3.90 kΩ, RB = 7.20 kΩ, and L = 646 mH.arrow_forwardIn the circuit of Figure P27.25, the switch S has been open for a long time. It is then suddenly closed. Take = 10.0 V, R1 = 50.0 k, R2 = 100 k, and C = 10.0 F. Determine the time constant (a) before the switch is closed and (b) after the switch is closed. (c) Let the switch be closed at t = 0. Determine the current in the switch as a function of time. Figure P27.25 Problems 25 and 26.arrow_forward
- In the circuit of Figure P27.25, the switch S has been open for a long time. It is then suddenly closed. Determine the time constant (a) before the switch is closed and (b) after the switch is closed. (c) Let the switch be closed at t = 0. Determine the current in the switch as a function of time. Figure P27.25 Problems 25 and 26.arrow_forwardWhen the switch is open in Figure 18.8, power Po is delivered to the resistor R1. When the switch is closed, which of the following is true about the power Pc delivered to R1? (Neglect the internal resistance of the battery.) (a) Pc Po (b) Pc = Po (c) Pc Po Figure 18.8 (Quick Quizzes 18.5 and 18.6)arrow_forwardWhen the switch is open in Figure 18.8, power Po is delivered to the resistor R1. When the switch is closed, which of the following is true about the power Pc delivered to R1? (Neglect the internal resistance of the battery.) (a) Pc Po (b) Pc = Po (c) Pc Po Figure 18.8 (Quick Quizzes 18.5 and 18.6)arrow_forward
- A motor in normal operation carries a direct current of 0.850 A when connected to a 120-V power supply. The resistance of the motor windings is 11.8 . While in normal operation, (a) what is the back emf generated by the motor? (b) At what rate is internal energy produced in the windings? (c) What If? Suppose a malfunction slops the motor shaft from rotating. At what rate will internal energy be produced in the windings in this case? (Most motors have a thermal switch that will turn off the motor to prevent overheating when this stalling occurs.)arrow_forwardWith the switch in the circuit of Figure 21.18a open, there is no current in R2. There is current in R1, however, and it is measured with the ammeter at the right side of the circuit. If the switch is closed (Fig. 21.18b), there is current in R2. What happens to the reading on the ammeter when the switch is closed? (a) The reading increases. (b) The reading decreases. (c) The reading does not change.arrow_forwardFind the direction of the current in the resistor shown in Figure P20.16 (a) at the instant the switch is closed, (b) after the switch has been closed for several minutes, and (c) at the instant the switch is opened. Figure P20.16arrow_forward
- A moving coil ammeter gives a full scale deflection for a current i = 60 mA and its coil has a resistance RC = 0.5 Ω. It is provided with a multiplier resistance Rm = 2.5 Ω added in series. What is the full scale deflection in volts of this modified ammeter? Select one: a. 30 mV b. 24 mV c. 150 mV d. 180 mVarrow_forwardThe circuit contains three resistors, A, B, and C, which have equal resistances. epsilon = 110V. Which resistor generates the most thermal energy after the switch is closed? a.B b.A c.All three generate the same amount of thermal energy. d.C e.A and Barrow_forwardIn the figure R1 = 9.81 kΩ, R2 = 15.4 kΩ, C = 0.433 μF, and the ideal battery has emf ε = 18.0 V. First, the switch is closed a long time so that the steady state is reached. Then the switch is opened at time t = 0. What is the current in resistor 2 at t = 3.60 ms?arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning