Four resistors and a battery of negligible internal resistance are assembled to make the circuit in Fig. 26.34.
A 90.0-V battery has an internal resistance of r=8.23Ω.
What is the reading of a voltmeter having a resistance of RV=425Ω when placed across the terminals of the battery?
b) What maximum value may the ratio r/RV have if the error in the reading of the emf of a battery is not to exceed 4.0%?
A resistor and capacitor are connected in series to an emf source. The time constant for the circuit is 0.870 s.
a) A second capacitor, identical to the first, is added in series. What is the time constant for this new circuit?
b) In the original circuit a second capacitor, indentical to the first, is connected in parallel with the first capacitor: What is the time constant for this new circuit?
A 20.0-m-long cable consists of a solid-inner, cylindrical, nickel core 10.0 cm in diameter surrounded by a solid outer cylindrical shell of copper 10 cm in inside diameter and 20 cm in outside diameter. The resistivity of nickel is 7.8.10-8Α.m, copper: 1.72.10-8Α.m.
a) What is the resistance of this cable?
b) If we think of this cable as a single material, what is its equivalent resistivity?
a) Find the current through the battery and each resistor in the circuit shown in Fig. 26.53.
b) What is the equivalent resistance of the resistor network?
Fig. 26.61
employs a convention often used in circuit diagrams. The battary (or other power supply) is not shown explicitly. It is understood that the point at the top, labeled "18V", is connected to the positive terminal of 18-V battery having negligible internal resistance, and that the "ground" symbol at the bottom is connected to the negative terminal of the battery. The circuit is completed through the battery, even thought it is not shown on the diagam.a) What is the potential of point a with respect to point b in fig 26.61 when switch S is open?
b) Which point, a or b, is at the higher potential?
c) What is the final potential of point b with respect to ground when switch S is closed?
d) How much does the charge on each capacitor change when S is closed?
A 2.36-µF capacitor that is initially uncharged is connected in series with a 4.26-Ω resistor and an emf source with ε=120V and negligible internal resistance.
a) Just after the connection is made, what is
i) the rate at which electrical energy is being dissipated in the resistor?
ii) the rate at which the electrical energy stored in the capacitor is increasing?
iii) the electrical power output of the source?
How do the answers to parts (i), (ii), and (iii) compare?
b) Answer the same questions as in part (a) at a long time after the connection is made.
c) Answer the same questions as in part (a) at the instant when the charge on the capacitor is one half its final value