chapter 27 current and resistance
about 0.200 mA. How much power does the neuron
41. Suppose your portable DVD player draws a current
of 350mA at 6.00V. How much power does the player
42. Review. A well-insulated electric water heater warms
109kg of water from 20.0°C to 49.0°C in 25.0 min.
Find the resistance of its heating element, which is con-
nected across a 240-V potential difference.
43. A 100-W lightbulb connected to a 120-V source expe-
riences a voltage surge that produces 140 V for a
moment. By what percentage does its power output
increase? Assume its resistance does not change.
44. The cost of energy delivered to residences by electrical
transmission varies from $0.070/kWh to $0.258/kWh
throughout the United States; $0.110/kWh is the aver-
age value. At this average price, calculate the cost of
(a) leaving a 40.0-W porch light on for two weeks while
you are on vacation, (b) making a piece of dark toast in
3.00 min with a 970-W toaster, and (c) drying a load of
clothes in 40.0min in a 5.20 3 103-W dryer.
45. Batteries are rated in terms of ampere-hours (A ? h).
For example, a battery that can produce a current of
2.00A for 3.00 h is rated at 6.00 A ? h. (a) What is the
total energy, in kilowatt-hours, stored in a 12.0-V battery
rated at 55.0A ? h? (b) At $0.110 per kilowatt-hour, what
is the value of the electricity produced by this battery?
46. Residential building codes typically require the use
of 12-gauge copper wire (diameter 0.205 cm) for wir-
ing receptacles. Such circuits carry currents as large as
20.0 A. If a wire of smaller diameter (with a higher gauge
number) carried that much current, the wire could rise
to a high temperature and cause a fire. (a) Calculate
the rate at which internal energy is produced in 1.00 m
of 12-gauge copper wire carrying 20.0 A. (b) What If?
Repeat the calculation for a 12-gauge aluminum wire.
(c) Explain whether a 12-gauge aluminum wire would
be as safe as a copper wire.
47. Assuming the cost of energy from the electric company
is $0.110/kWh, compute the cost per day of operating a
lamp that draws a current of 1.70 A from a 110-V line.
48. An 11.0-W energy-efficient fluorescent lightbulb is
designed to produce the same illumination as a con-
ventional 40.0-W incandescent lightbulb. Assuming a
cost of $0.110/kWh for energy from the electric com-
pany, how much money does the user of the energy-
efficient bulb save during 100 h of use?
49. A coil of Nichrome wire is 25.0 m long. The wire has
a diameter of 0.400 mm and is at 20.0°C. If it carries a
current of 0.500 A, what are (a) the magnitude of the
electric field in the wire and (b) the power delivered
to it? (c) What If? If the temperature is increased to
340°C and the potential difference across the wire
remains constant, what is the power delivered?
50. Review. A rechargeable battery of mass 15.0 g deliv-
ers an average current of 18.0 mA to a portable DVD
player at 1.60V for 2.40 h before the battery must be
device must have an overall resistance of R
5 10.0 V
independent of temperature and a uniform radius of
r 5 1.50 mm. Ignore thermal expansion of the cylinders
and assume both are always at the same temperature.
(a) Can she meet the design goal with this method?
(b) If so, state what you can determine about the lengths
of each segment. If not, explain.
33. An aluminum wire with a diameter of 0.100 mm has a
uniform electric field of 0.200 V/m imposed along its
entire length. The temperature of the wire is 50.0°C.
Assume one free electron per atom. (a) Use the infor-
mation in Table 27.2 to determine the resistivity of
aluminum at this temperature. (b) What is the current
density in the wire? (c)What is the total current in the
wire? (d) What is the drift speed of the conduction
electrons? (e) What potential difference must exist
between the ends of a 2.00-m length of the wire to pro-
duce the stated electric field?
34. Review. An aluminum rod has a resistance of 1.23 V at
20.0°C. Calculate the resistance of the rod at 120°C by
accounting for the changes in both the resistivity and
the dimensions of the rod. The coefficient of linear
expansion for aluminum is 2.40 3 1026 (°C)21.
35. At what temperature will aluminum have a resistivity
that is three times the resistivity copper has at room
Section 27.6 Electrical Power
36. Assume that global lightning on the Earth constitutes
a constant current of 1.00 kA between the ground and
an atmospheric layer at potential 300 kV. (a) Find the
power of terrestrial lightning. (b) For comparison, find
the power of sunlight falling on the Earth. Sunlight
has an intensity of 1 370 W/m2 above the atmosphere.
Sunlight falls perpendicularly on the circular pro-
jected area that the Earth presents to the Sun.
37. In a hydroelectric installation, a turbine delivers
1 500 hp to a generator, which in turn transfers 80.0%
of the mechanical energy out by electrical transmis-
sion. Under these conditions, what current does the
generator deliver at a terminal potential difference of
2 000 V?
38. A Van de Graaff generator (see Fig. 25.23) is operat-
ing so that the potential difference between the high-
potential electrode B and the charging needles at A
is 15.0 kV. Calculate the power required to drive the
belt against electrical forces at an instant when the
effective current delivered to the high-potential elec-
trode is 500 mA.
39. A certain waffle iron is rated at 1.00 kW when con-
nected to a 120-V source. (a) What current does the
waffle iron carry? (b) What is its resistance?
40. The potential difference across a resting neuron in the
human body is about 75.0 mV and carries a current of
48 W of power when connected across a 20-V battery.
What length of wire is required?
58. Determine the temperature at which the resistance
of an aluminum wire will be twice its value at 20.0°C.
Assume its coefficient of resistivity remains constant.
59. A car owner forgets to turn off the headlights of his
car while it is parked in his garage. If the 12.0-V bat-
tery in his car is rated at 90.0 A ? h and each headlight
requires 36.0W of power, how long will it take the bat-
tery to completely discharge?
60. Lightbulb A is marked “25 W 120 V,” and lightbulb B
is marked “100 W 120 V.” These labels mean that each
lightbulb has its respective power delivered to it when
it is connected to a constant 120-V source. (a) Find
the resistance of each lightbulb. (b) During what time
interval does 1.00C pass into lightbulb A? (c) Is this
charge different upon its exit versus its entry into the
lightbulb? Explain. (d) In what time interval does
1.00 J pass into lightbulb A? (e) By what mechanisms
does this energy enter and exit the lightbulb? Explain.
(f) Find the cost of running lightbulb A continuously
for 30.0 days, assuming the electric company sells its
product at $0.110 per kWh.
61. One wire in a high-voltage transmission line carries
1000A starting at 700 kV for a distance of 100 mi. If
the resistance in the wire is 0.500 V/mi, what is the
power loss due to the resistance of the wire?
62. An experiment is conducted to measure the electri-
cal resistivity of Nichrome in the form of wires with
different lengths and cross-sectional areas. For one
set of measurements, a student uses 30-gauge wire,
which has a cross- sectional area of 7.30 3 1028 m2.
The student measures the potential difference across
the wire and the current in the wire with a voltme-
ter and an ammeter, respectively. (a) For each set of
measurements given in the table taken on wires of
three different lengths, calculate the resistance of the
wires and the corresponding values of the resistiv-
ity. (b)What is the average value of the resistivity?
(c)Explain how this value compares with the value
given in Table27.2.
r (V ? m)
63. A charge Q is placed on a capacitor of capacitance C.
The capacitor is connected into the circuit shown in
Figure P27.63, with an open switch, a resistor, and an
initially uncharged capacitor of capacitance 3C. The
recharged. The recharger maintains a potential dif-
ference of 2.30 V across the battery and delivers a
charging current of 13.5 mA for 4.20 h. (a) What is the
efficiency of the battery as an energy storage device?
(b) How much internal energy is produced in the bat-
tery during one charge–discharge cycle? (c) If the
battery is surrounded by ideal thermal insulation and
has an effective specific heat of 975 J/kg ? °C, by how
much will its temperature increase during the cycle?
51. A 500-W heating coil designed to operate from 110 V
is made of Nichrome wire 0.500 mm in diameter.
(a) Assuming the resistivity of the Nichrome remains
constant at its 20.0°C value, find the length of wire
used. (b) What If? Now consider the variation of resis-
tivity with temperature. What power is delivered to the
coil of part (a) when it is warmed to 1 200°C?
52. Why is the following situation impossible? A politician is
decrying wasteful uses of energy and decides to focus
on energy used to operate plug-in electric clocks in
the United States. He estimates there are 270 million
of these clocks, approximately one clock for each per-
son in the population. The clocks transform energy
taken in by electrical transmission at the average rate
2.50 W. The politician gives a speech in which he com-
plains that, at today’s electrical rates, the nation is los-
ing $100 million every year to operate these clocks.
53. A certain toaster has a heating element made of
Nichrome wire. When the toaster is first connected
to a 120-V source (and the wire is at a temperature
of 20.0°C), the initial current is 1.80 A. The current
decreases as the heating element warms up. When the
toaster reaches its final operating temperature, the cur-
rent is 1.53 A. (a) Find the power delivered to the toaster
when it is at its operating temperature. (b) What is the
final temperature of the heating element?
54. Make an order-of-magnitude estimate of the cost of
one person’s routine use of a handheld hair dryer for 1
year. If you do not use a hair dryer yourself, observe or
interview someone who does. State the quantities you
estimate and their values.
55. Review. The heating element of an electric coffee
maker operates at 120 V and carries a current of 2.00 A.
Assuming the water absorbs all the energy delivered to
the resistor, calculate the time interval during which
the temperature of 0.500 kg of water rises from room
temperature (23.0°C) to the boiling point.
56. A 120-V motor has mechanical power output of 2.50 hp.
It is 90.0% efficient in converting power that it takes in by
electrical transmission into mechanical power. (a) Find
the current in the motor. (b) Find the energy delivered
to the motor by electrical transmission in 3.00 h of oper-
ation. (c)If the electric company charges $0.110/kWh,
what does it cost to run the motor for 3.00 h?
57. A particular wire has a resistivity of 3.0 3 1028 V ? m
and a cross-sectional area of 4.0 3 1026 m2. A length
of this wire is to be used as a resistor that will receive
chapter 27 current and resistance
70. The strain in a wire can be monitored and computed
by measuring the resistance of the wire. Let L
resent the original length of the wire, A
cross-sectional area, R
the original resis-
tance between its ends, and d 5 DL/L
5 (L 2 L
the strain resulting from the application of tension.
Assume the resistivity and the volume of the wire do
not change as the wire stretches. (a) Show that the
resistance between the ends of the wire under strain
is given by R 5 R
(1 1 2d 1 d2). (b)If the assumptions
are precisely true, is this result exact or approximate?
Explain your answer.
71. An oceanographer is studying how the ion concen-
tration in seawater depends on depth. She makes a
measurement by lowering into the water a pair of con-
centric metallic cylinders (Fig. P27.71) at the end of
a cable and taking data to determine the resistance
between these electrodes as a function of depth. The
water between the two cylinders forms a cylindrical
shell of inner radius r
, outer radius r
, and length L
much larger than r
. The scientist applies a potential
difference DV between the inner and outer surfaces,
producing an outward radial current I. Let r represent
the resistivity of the water. (a)Find the resistance of
the water between the cylinders in terms of L, r, r
. (b) Express the resistivity of the water in terms
of the measured quantities L, r
, DV, andI.
72. Why is the following situation impossible? An inquisitive
physics student takes a 100-W incandescent lightbulb
out of its socket and measures its resistance with an
ohmmeter. He measures a value of 10.5 V. He is able to
connect an ammeter to the lightbulb socket to cor-
rectly measure the current drawn by the bulb while
operating. Inserting the bulb back into the socket and
operating the bulb from a 120-V source, he measures
the current to be 11.4 A.
73. The temperature coefficients of resistivity a in Table
27.2 are based on a reference temperature T
20.0°C. Suppose the coefficients were given the symbol
a9 and were based on a T
of 0°C. What would the coef-
ficient a9 for silver be? Note: The coefficient a satisfies
r 5 r
[1 1 a(T 2 T
)], where r
is the resistivity of the
material at T
5 20.0°C. The coefficient a9 must satisfy
the expression r 5 r9
[1 1 a9T], where r9
is the resistiv-
ity of the material at 0°C.
74. A close analogy exists between the flow of energy by
heat because of a temperature difference (see Sec-
tion 20.7) and the flow of electric charge because of a
switch is then closed, and the circuit comes to equilib-
rium. In terms of Q and C, find (a) the final poten-
tial difference between the plates of each capacitor,
(b) the charge on each capacitor, and (c) the final
energy stored in each capacitor. (d) Find the internal
energy appearing in the resistor.
64. Review. An office worker uses an immersion heater
to warm 250 g of water in a light, covered, insulated
cup from 20.0°C to 100°C in 4.00 min. The heater
is a Nichrome resistance wire connected to a 120-V
power supply. Assume the wire is at 100°C throughout
the 4.00-min time interval. (a) Specify a relationship
between a diameter and a length that the wire can
have. (b) Can it be made from less than 0.500 cm3 of
65. An x-ray tube used for cancer therapy operates at
4.00 MV with electrons constituting a beam current of
25.0 mA striking a metal target. Nearly all the power
in the beam is transferred to a stream of water flowing
through holes drilled in the target. What rate of flow,
in kilograms per second, is needed if the rise in tem-
perature of the water is not to exceed 50.0°C?
66. An all-electric car (not a hybrid) is designed to run
from a bank of 12.0-V batteries with total energy stor-
age of 2.00 3 107 J. If the electric motor draws 8.00 kW
as the car moves at a steady speed of 20.0 m/s, (a) what
is the current delivered to the motor? (b) How far can
the car travel before it is “out of juice”?
67. A straight, cylindrical wire lying along the x axis has
a length of 0.500 m and a diameter of 0.200 mm. It
is made of a material described by Ohm’s law with a
resistivity of r5 4.00 3 1028 V ? m. Assume a poten-
tial of 4.00 V is maintained at the left end of the wire
at x 5 0. Also assume V 5 0 at x 5 0.500 m. Find
(a) the magnitude and direction of the electric field in
the wire, (b) the resistance of the wire, (c) the magnitude
and direction of the electric current in the wire, and
(d) the current density in the wire. (e)Show that E 5 rJ.
68. A straight, cylindrical wire lying along the x axis has
a length L and a diameter d. It is made of a material
described by Ohm’s law with a resistivity r. Assume
potential V is maintained at the left end of the wire at
x 5 0. Also assume the potential is zero at x 5 L. In
terms of L, d, V, r, and physical constants, derive
expressions for (a) the magnitude and direction of the
electric field in the wire, (b) the resistance of the wire,
(c) the magnitude and direction of the electric current
in the wire, and (d) the current density in the wire.
(e) Show that E 5 rJ.
69. An electric utility company supplies a customer’s house
from the main power lines (120 V) with two copper
wires, each of which is 50.0 m long and has a resistance
of 0.108V per 300 m. (a) Find the potential difference
at the customer’s house for a load current of 110 A. For
this load current, find (b) the power delivered to the
customer and (c)the rate at which internal energy is
produced in the copper wires.
the left edge of the dielectric is at a distance x from the
center of the capacitor. (b) If the dielectric is removed
at a constant speed v, what is the current in the circuit
as the dielectric is being withdrawn?
78. The dielectric material between the plates of a parallel-
plate capacitor always has some nonzero conductiv-
ity s. Let A represent the area of each plate and d the
distance between them. Let k represent the dielectric
constant of the material. (a) Show that the resistance
R and the capacitance C of the capacitor are related by
(b) Find the resistance between the plates of a 14.0-nF
capacitor with a fused quartz dielectric.
79. Gold is the most ductile of all metals. For example, one
gram of gold can be drawn into a wire 2.40 km long.
The density of gold is 19.3 3 103 kg/m3, and its resistiv-
ity is 2.44 3 1028 V ? m. What is the resistance of such a
wire at 20.0°C?
80. The current–voltage characteristic curve for a semicon-
ductor diode as a function of temperature T is given by
I 5 I
T 2 1)
Here the first symbol e represents Euler’s number,
the base of natural logarithms. The second e is the
magnitude of the electron charge, the k
Boltzmann’s constant, and T is the absolute tempera-
ture. (a) Set up a spreadsheet to calculate I and R 5
DV/I for DV 5 0.400 V to 0.600 V in increments of
0.005 V. Assume I
5 1.00 nA. (b) Plot R versus DV for
T 5 280 K, 300 K, and 320 K.
81. The potential difference across the filament of a light-
bulb is maintained at a constant value while equilib-
rium temperature is being reached. The steady-state
current in the bulb is only one-tenth of the current
drawn by the bulb when it is first turned on. If the tem-
perature coefficient of resistivity for the bulb at 20.0°C
is 0.004 50 (°C)21 and the resistance increases linearly
with increasing temperature, what is the final operat-
ing temperature of the filament?
82. A more general definition of the temperature coeffi-
cient of resistivity is
where r is the resistivity at temperature T. (a) Assum-
ing a is constant, show that
r 5 r
ea(T 2 T
is the resistivity at temperature T
. (b) Using
the series expansion ex < 1 1 x for x ,, 1, show that
the resistivity is given approximately by the expression
r 5 r
[1 1 a(T 2 T
)] for a(T 2 T
) ,, 1
83. A spherical shell with inner radius r
and outer radius
is formed from a material of resistivity r. It carries
potential difference. In a metal, energy dQ and electri-
cal charge dq are both transported by free electrons.
Consequently, a good electrical conductor is usually a
good thermal conductor as well. Consider a thin con-
ducting slab of thickness dx, area A, and electrical
conductivity s, with a potential difference dV between
opposite faces. (a) Show that the current I 5 dq/dt is
given by the equation on the left:
Charge conduction Thermal conduction
In the analogous thermal conduction equation on the
right (Eq. 20.15), the rate dQ/dt of energy flow by heat
(in SI units of joules per second) is due to a tempera-
ture gradient dT/dx in a material of thermal conductiv-
ity k. (b) State analogous rules relating the direction
of the electric current to the change in potential and
relating the direction of energy flow to the change in
75. Review. When a straight wire is warmed, its resistance is
given by R 5 R
[1 1 a(T 2 T
)] according to Equation
27.20, where a is the temperature coefficient of resistiv-
ity. This expression needs to be modified if we include
the change in dimensions of the wire due to thermal
expansion. For a copper wire of radius 0.100 0 mm and
length 2.000 m, find its resistance at 100.0°C, includ-
ing the effects of both thermal expansion and tempera-
ture variation of resistivity. Assume the coefficients are
known to four significant figures.
76. Review. When a straight wire is warmed, its resistance
is given by R 5 R
[1 1 a(T 2 T
)] according to Equa-
tion 27.20, where a is the temperature coefficient of
resistivity. This expression needs to be modified if we
include the change in dimensions of the wire due to
thermal expansion. Find a more precise expression for
the resistance, one that includes the effects of changes
in the dimensions of the wire when it is warmed. Your
final expression should be in terms of R
, T, T
temperature coefficient of resistivity a, and the coef-
ficient of linear expansion a9.
77. Review. A parallel-plate capacitor consists of square
plates of edge length , that are separated by a dis-
tance d, where d ,, ,. A potential difference DV is
maintained between the plates. A material of dielec-
tric constant k fills half the space between the plates.
The dielectric slab is withdrawn from the capacitor as
shown in Figure P27.77. (a) Find the capacitance when
chapter 27 current and resistance
85. A material of resistivity r is formed into the shape of a
truncated cone of height h as shown in Figure P27.85.
The bottom end has radius b, and the top end has
radius a. Assume the current is distributed uniformly
over any circular cross section of the cone so that the
current density does not depend on radial position.
(The current density does vary with position along the
axis of the cone.) Show that the resistance between the
two ends is
current radially, with uniform density in all directions.
Show that its resistance is
84. Material with uniform resistivity r is formed into a
wedge as shown in Figure P27.84. Show that the resis-
tance between face A and face B of this wedge is
A technician repairs a connection
on a circuit board from a computer.
In our lives today, we use various
items containing electric circuits,
including many with circuit boards
much smaller than the board shown
in the photograph. These include
handheld game players, cell phones,
and digital cameras. In this chapter,
we study simple types of circuits
and learn how to analyze them.
28.1 Electromotive Force
28.2 Resistors in Series
28.3 Kirchhoff’s Rules
28.4 RC Circuits
28.5 Household Wiring and
c h a p p t t e r
In this chapter, we analyze simple electric circuits that contain batteries, resistors, and
capacitors in various combinations. Some circuits contain resistors that can be combined
using simple rules. The analysis of more complicated circuits is simplified using Kirchhoff’s
rules, which follow from the laws of conservation of energy and conservation of electric
charge for isolated systems. Most of the circuits analyzed are assumed to be in steady state,
which means that currents in the circuit are constant in magnitude and direction. A current
that is constant in direction is called a direct current (DC). We will study alternating current
(AC), in which the current changes direction periodically, in Chapter 33. Finally, we discuss
electrical circuits in the home.
28.1 Electromotive Force
In Section 27.6, we discussed a circuit in which a battery produces a current. We
will generally use a battery as a source of energy for circuits in our discussion.
Because the potential difference at the battery terminals is constant in a particular
circuit, the current in the circuit is constant in magnitude and direction and is
called direct current. A battery is called either a source of electromotive force or, more
commonly, a source of emf. (The phrase electromotive force is an unfortunate historical
term, describing not a force, but rather a potential difference in volts.) The emf
of a battery is the maximum possible voltage the battery can provide between its
terminals. You can think of a source of emf as a “charge pump.” When an electric
potential difference exists between two points, the source moves charges “uphill”
from the lower potential to the higher.
We shall generally assume the connecting wires in a circuit have no resistance.
The positive terminal of a battery is at a higher potential than the negative terminal.
chapter 28 Direct-current circuits
Because a real battery is made of matter, there is resistance to the flow of charge
within the battery. This resistance is called internal resistance r. For an idealized
battery with zero internal resistance, the potential difference across the battery
(called its terminal voltage) equals its emf. For a real battery, however, the terminal
voltage is not equal to the emf for a battery in a circuit in which there is a current.
To understand why, consider the circuit diagram in Figure 28.1a. We model the bat-
tery as shown in the diagram; it is represented by the dashed rectangle containing
an ideal, resistance-free emf
in series with an internal resistance r. A resistor of
resistance R is connected across the terminals of the battery. Now imagine moving
through the battery from a to d and measuring the electric potential at various
locations. Passing from the negative terminal to the positive terminal, the potential
increases by an amount
. As we move through the resistance r, however, the poten-
tial decreases by an amount Ir, where I is the current in the circuit. Therefore, the
terminal voltage of the battery DV 5 V
From this expression, notice that
is equivalent to the open-circuit voltage, that
is, the terminal voltage when the current is zero. The emf is the voltage labeled on
a battery; for example, the emf of a D cell is 1.5 V. The actual potential difference
between a battery’s terminals depends on the current in the battery as described by
Equation 28.1. Figure 28.1b is a graphical representation of the changes in electric
potential as the circuit is traversed in the clockwise direction.
Figure 28.1a shows that the terminal voltage DV must equal the potential differ-
ence across the external resistance R, often called the load resistance. The load resis-
tor might be a simple resistive circuit element as in Figure 28.1a, or it could be the
resistance of some electrical device (such as a toaster, electric heater, or lightbulb)
connected to the battery (or, in the case of household devices, to the wall outlet).
The resistor represents a load on the battery because the battery must supply energy
to operate the device containing the resistance. The potential difference across the
load resistance is DV 5 IR. Combining this expression with Equation 28.1, we see that
Figure 28.1a shows a graphical representation of this equation. Solving for the cur-
Equation 28.3 shows that the current in this simple circuit depends on both the
load resistance R external to the battery and the internal resistance r. If R is much
greater than r, as it is in many real-world circuits, we can neglect r.
Multiplying Equation 28.2 by the current I in the circuit gives
= I2R 1 I2r
Equation 28.4 indicates that because power P 5 I DV (see Eq. 27.21), the total power
associated with the emf of the battery is delivered to the external load
resistance in the amount I2R and to the internal resistance in the amount I2r.
Q uick Quiz 28.1 To maximize the percentage of the power from the emf of a bat-
tery that is delivered to a device external to the battery, what should the internal
resistance of the battery be? (a) It should be as low as possible. (b) It should be as
high as possible. (c) The percentage does not depend on the internal resistance.
(a) Circuit diagram
of a source of emf
(in this case,
a battery), of internal resistance
r, connected to an external resis-
tor of resistance R. (b)Graphical
representation showing how the
electric potential changes as the
circuit in (a) is traversed clockwise.
Pitfall Prevention 28.1
What Is Constant in a Battery?
It is a common misconception that
a battery is a source of constant
current. Equation 28.3 shows that
is not true. The current in the cir-
cuit depends on the resistance R
connected to the battery. It is also
not true that a battery is a source
of constant terminal voltage as
shown by Equation 28.1. A battery
is a source of constant emf.
Example 28.1 Terminal Voltage of a Battery
A battery has an emf of 12.0 V and an internal resistance of 0.050 0 V. Its terminals are connected to a load resistance
of 3.00 V.
Documents you may be interested
Documents you may be interested