physics chapter 22-23 review
a fuse is an automatic switch that opens when the current reaches a threshold value
false (circuit breaker)
a circuit breaker is a short piece of metal that melts when a current that is too large passes through it
false (fuse)
electric energy is transferred from generating stations to consumers premises at extremely low voltage
false (high voltage)
an ampere is a unit used by electric companies to measure electrical energy use
false (kW hour)
one kilowatt-hour is equal to the energy consumed by an electric device of 1 W for 1 hour
false (kW)
ammeters have a very high resistance so as to cause the smallest possible change in currents and voltages in the circuit
false (low resistance)
a parallel connection is a type of electric circuit in which there is a single current path
false (multiple paths)
a series connection is a type of electric circuit in which there are multiple paths
false (single path)
A short piece of metal that melts when a large current passes through it is a:
fuse
a ________ is described as a piece of metal that acts as a safety device in a circuit which melts and stops the flow of current
fuse
a ________ is described as a device that detects current differences and then opens the circuit preventing electrocution
ground fault interrupter
if a resistor is added to a series circuit, the equivalent resistance
increases
a ____ is an energy unit used to measure electric energy use by power companies
kilowatt-hour
a ______ is equal to 1000 watts delivered continuously for 3,600 seconds
kilowatt-hour
The number of current paths in a series circuit is:
one
a ________ is described as a type of circuit in which there are several current paths
parallel circuit
a ________ is a type of electric circuit in which there are multiple paths, whereas a _________ is a type of electric circuit in which there is a single path
parallel connection, series connection
_________ is described as a property that determines how much current will flow for a given battery voltage
resistance
a ____________ is described as a device with specific resistance and is used to control current
resistor
a __________ is described as a device with specific resistance and is used to control current. whereas a _____ converts chemical energy to electric energy
resistor, battery
a _______ is described as a type of circuit in which there is only a single current path
series circuit
a ______ is a type of electric circuit in which there is a single current path
series connection
a ______ occurs when a very low resistance circuit is formed and can easily start a fire
short circuit
in the circuit shown below, the ammeter shows that there is a current. However, the bulb doesn't light because:
the variable resistance has a large value
A circuit, which includes series and parallel branches, is called a combined series-parallel circuit
true
In order to measure the current through a resistor, an ammeter is placed in series with the resistor
true
a ground-fault interrupter in an electric outlet prevents injuries because it contains an electronic circuit that detects differences in current cause by an extra path and opens the circuit
true
a short circuit occurs when a circuit with a very low resistance is formed
true
an electric circuit is a closed loop or pathway that allows electric charges to flow
true
an electric current is a flow of charged particles
true
arc fault circuit interrupters use electronic detectors to respond to the electric signals associated with arcing; they can shut down a circuit in many cases where a circuit breaker would react
true
as current moves through any circuit, the net change in potential must be zero
true
circuit breakers are connected in series so that the circuit will open in case of dangerously high current
true
fuses and circuit breakers protects against the large currents created by a short circuit
true
it is necessary to understand series and parallel circuits to fully understand residential wiring
true
resistance in a property that determines how much current will flow in a circuit
true
the cables used to transfer electric energy from the generating station to the consumers must be of low resistance to reduce losses due to joule heating
true
the flow of electric charge of current that is equal to one coulomb per second is an ampere
true
to measure the potential drop across a resistor, a voltmeter is connected in parallel with a resistor
true
voltage dividers are often used with sensors, such as photosensors
true
voltmeters are designed to have a very high resistance so as to cause the smallest possible change in currents and voltages in the circuit
true
a ________ is described as a series circuit that is used to produce a lower voltage from a higher voltage battery
voltage divider
a _______ is described as a device that is used to measure voltage drop across any part of a circuit
voltmeter
a _______ is used to measure the voltage drop across a portion of a circuit
voltmeter
A car panel lamp has a resistance of 33 ohms when it is placed across a 12 V battery. What is the current through the circuit?
.36 A
A lightbulb uses 100 W of power when connected across 120 V electric line. What is the current through the lightbulb?
0.8 A
a hair dryer with a resistance of 12.0 ohms and a lamp with a resistance of 125 ohms are connected in parallel to a 125 V source through a 1.50 ohm resistor in a series. find the current through the lamp when the hair dryer is on
0.880 A
A motor with an operating resistance of 32 ohms is connected to a voltage source. The current in the circuit is 3.8 A. What is the voltage of the source?
1.2 x10^2 V
a sensor uses 2.0x10^-4 A of current when it is operated by a 3.0 V battery. what is the resistance of the sensor circuit?
1.5x10^4 ohms
A lamp draws a current of 0.50 A when it is connected to a 120 V source. What is the resistance of the lamp?
2.4 x 10^2 ohms
a parallel circuit has four branch currents: 120 mA, 380mA, 250 mA, and 2.1 A. how much current is supplied by the source?
2.9 A
three resistors of 1.00x10^2 ohms, 3.90 kilo-ohms. and 1.00 kilo-ohms plate connected in series across a 2.00x10^2-V battery. the voltage drop across the resistor value 1.00 kilo-ohms is:
40.0 V
A 4.0-ohm resistor, an 8.0-ohm resistor, and a 10.0-ohm resistor are connected in series across an 11-V battery. The total voltage drop across the 4.0-ohm and 8.0-ohm resistors is:
6.0 V
In the circuit shown below, which bulb, when burned out, will cause all other bulbs to stop glowing?
A
Which device measures the current in a circuit?
Ammeter
a _______ is described as a low resistance device connected in series that is used to measure current.
ammeter
a ________ is a device that is used to measure the current in any branch or part of a circuit
ammeter
a ______ is described as the flow of electric charge of current equal to one coulomb per second
ampere
the flow of electric charge or current equal to one coulomb per second is a __________
ampere
a _______ is described as a device that converts chemical energy to electric energy
battery
An automatic switch that opens when the current reaches a set value is called:
circuit breaker
a _______ is described as an automatic switch that acts as a safeguard in an electric current
circuit breaker
a __________ is described as the flow of positive charges that move from a higher to lower potential energy
conventional current
in a series circuit, each circuit element has the same
current
if a resistor is added to a parallel circuit, the equivalent resistance
decreases
a ______ is described as a closed loop or pathway that allows electric charges to flow
electric circuit
a ________ is described as a closed loop or pathway that allows electric charges to flow, whereas a _______ is described as a flow of charged particles
electric circuit, electric current
a _____ is described as the flow of charged particles
electric current
a ________ is described as a flow of charged particles
electric current