Quiz 4-1
62 parts
1 point each
Part
1: Fill in the Blanks and Definitions
n
The flow of electrons is called _____________________
current
n
The charge of 6.14 x1018 electrons is called a
____________________ coulomb
n
The unit of measurement for current is the __________________ ampere
n
__________________ is the force that moves electrons in a circuit
voltage
n
__________________ is a general name for materials with high resistance
Insulators
n
__________________ is a general name for materials with low resistance
conductors
n
Write the symbol or letter for the following items in the space provided
|
Item |
Symbol |
|
10-3 |
m |
|
10-6 |
m |
|
103 |
K |
|
106 |
M |
n
One amp is the amount of current that flows in a conductor when one
____________ of charge
moves past a point in one second.
coulomb
n
What is the name of the single instrument used to measure
Ø
Resistance: ________________________________
Ohmmeter
Ø
Current: ___________________________________
Ammeter
Ø
Voltage: ___________________________________
Voltmeter
n
A resistor's ______________________ is the amount that it may vary and still
be acceptable.
tolerance
n
For each of the following, indicate whether the instrument is connected in
series with the item being
measure or in parallel (your answer should be either series or parallel).
Ø
Resistance: ________________________________
Parallel
Ø
Current: ___________________________________
Series
Ø
Voltage: ___________________________________
Parallel
n
List the 2 types of ground discussed in the text.
Ø
________________________________
Earth
Ø
________________________________
Electrical
n
Variable
resistors used to control current are called _________________
rheostats
n
The
relationship of current, voltage, and resistance is given by _______________
law.
Ohm's
n
Current
that flows in one direction and then the other is called
___________________________
alternating current
n
Current
that flows in one direction only is called ___________________________
direct current.
n
The
basic unit of power is the ____________________________
watt
n
The
_________________ is a device used to control a large flow of current by
means of a low
voltage, low current circuit.
relay
n
A
__________________ is a device used to transfer energy from one circuit to
another using
electromagnetic induction.
transformer
n
The
opposition to alternating current as a result of inductance or capacitance
is called
_________________ reactance.
n
Induced
emf in any circuit is always in such a direction as to oppose the effect
that produces it.
This is a statement of ________________ law.
Lenz's
n
_____________________
is an inherent property of an electrical circuit that opposes a change in
current. Inductance
n
The
total resistance to the flow of an alternating current as a result of
resistance and reactance is
called _________________________ impedance
n
A
__________________ is a device that temporarily stores an electric charge.
capacitor
n
An
__________________ is an electronic component that is used to produce
inductance in a
circuit. A coil is an example
of such a component.
inductor
n Ohm's law is valid for AC circuits, except that _________________ must be substituted for
resistance.
impedance
n
The
_______________
__________________ is the time period required for the voltage of a
capacitor in an RC circuit to increase to 63.2% of maximum value or decrease
to 36.7% of
maximum value. time constant
n
The
formula for capacitive reactance is XC = 1/2PfC.
Provide the units for each of the components
of this formula listed below.
a.
XC: __________________
ohms
b.
f: ____________________ hertz
c.
C: ___________________ farads
n
The
following formula was discussed in chapter 15.
Z = (R2 + XC2)1/2
a. Z is referred to as
________________________ impedance
b. The units of Z are
___________________ ohms
c. The units of R are
___________________ ohms
Part 2: Circuit Analysis- DC and Resistance
n
Given a circuit with a DC power supply of 9 volts and 3 resistors in series.
Each resistor has a
value of 1 ohms.
a. What is the total or
equivalent resistance in this circuit?
R1 + R2 + R3 = 3
b. What is the voltage drop
across each resistor?
The voltage drop is proportional to the resistance and they sum to the total
source.
Voltage drop across each resistor is 3 volts
n
Given a circuit with a DC power supply, supplying 9 volts and 4 resistors in
parallel. Each resistor
has a value of 2 ohms.
a. What is the total or
equivalent resistance in this circuit?
1/RT
= 1/2 + 1/2 + 1/2 + 1/2 = 2
gives RT = 2
b. What is the voltage drop
across each resistor?
9 volts
n
Given a circuit with a resistor rated at 2 ohms and 2 DC batteries,
connected in series, each rated
at 6 volts. What is the total
voltage in the circuit?
12 volts
n
Given a circuit with a resistor rated at 2 ohms and 2 DC batteries,
connected in parallel, each rated
at 6 volts. What is the total
voltage in the circuit?
6 volts
n
The following is an example of a _______________________ circuit
parallel
n
How much current is used by a 100-watt, 120 volt light bulb?
P = IE
100 = I(120) gives I = 100/120 = 0.83 amp
Part 3: Electronics Symbols
Electronic symbols are used extensively in circuits
to represent various electrical devices and components.
Provide a drawing in the space provided for each of the items named
below.
|
|
|
|
|
|
|
Resistor |
Inductor |
AC Power |
Ground |
Cell |
|
|
|
|
|
|
|
Capacitor |
Variable Capacitor |
Potentiometer |
Voltmeter |
Ammeter |
Part 4: Circuit Analysis - AC with RL and RC Circuits
n
Assume that you have 3 coils, each with inductance L.
a. Give an expression below for
the total inductance, LT if they are connected in series
LT = L + L + L = 3L
b. Give an expression below for
the total inductance, LT if they are connected in parallel.
1/LT = 1/L + 1/L + 1/L = 3/L
LT = L/3
n
Assume that you have 3 capacitors, each with capacitance C.
a. Give an expression below for
the total capacitance CT if they are connected in series.
1/CT
= 1/C + 1/C + 1/C
CT =
C/3
b. Give an expression below for
the total capacitance CT if they are connected in parallel.
CT = C + C + C = 3C
n
Assume that the voltage on the lines outside a residence is 2400 volts and
that it must be reduced
to 120 volts for use in a residence.
To do this a transformer is to be used. If there are 1000 turns
on the primary side of the transformer, how many turns should be on the
secondary side?
VS/VP
= NS/NP
gives NS = 5 turns