Electric circuits are protected against overloads and short circuits by means of a/an （）.
A . circuit breaker
B . amplifier
C . diode
D . capacitor
相似题目
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Fuses placed in series with a thermal trip-type circuit breaker are used for （）.
A . time-delay protection
B . short-circuit protection
C . short duration surge protection
D . sustained overload protectio
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Which four statements about Ethernet virtual circuit （EVC） infrastructure are true？ （）
A . EVC infrastructure is a Layer 3 platform-independent routing architecture that supports IP overEthernet services
B . Ethernet flow point （EFP） is configured on the main interface
C . Feature commands like MQC-based QoS policies can be specified
D . EVC infrastructure is a Layer 2 platform-independent bridging architecture that supports Ethernetservices
E . Each Ethernet flow point （EFP） matches a predefined VLAN tag-based criteria
F . Ethernet flow point （EFP） is configured on the VLAN interface
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Inductance is the property of an electric circuit that （）
A、opposes any change in the applied voltage
B、opposes any change in the current flow through the circuit
C、aids any changes in the applied voltage
D、aids any changes in the current through the circuit
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Main engine room control console alarms are to be of the self monitoring type, meaning that an open circuit to a particular alarm circuit will （）
A、cause an alarm condition
B、secure power to the indicator
C、secure power to the monitored device
D、automatically reclose within 10 seconds.
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Tools with （）handles should be used to check electric circuit.
A . plastic
B . metal
C . stainless steel
D . copper
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In motorships，there are two main circuits, （）.
A . one salt water, one fresh water
B . one salt water, one fuel
C . one fresh water, one fuel
D . one steam, one fuel
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Operational amplifiers, used primarily in analog circuits, are characterized by（）
A . high input impedance, high gain and low output impedance
B . high input impedance, high gain and high output impedance
C . low input impedance, low gain and high output impedance
D . low input impedance, high gain and low output impedance
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You are provisioning a DS-1 circuit on an ONS 15454 2F-BLSR with a XC-10G card. Each VT1.5 connection must also terminate via the STS matrix. On the originating circuit node, how many STS ports are now available for VT1.5 circuits?（）
A . 2
B . 3
C . 4
D . 20
E . 22
F . 24
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A transformer in an electric circuit serves to （）
A . generate its own electrical power
B . transform electrical energy into mechanical energy
C . increase or decrease circuit voltage as required
D . convert AC current to DC current
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In a three-phase circuit, the phase voltages are （）
A . 120°apart
B . 160°apart
C . 180°apart
D . 360°apart
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It has become necessary to configure an existing serial interface to accept a second Frame Relay virtual circuit.Which of the following processes are required to accomplish this task?（）
A . configure static frame relay map entries for each subinterface network.
B . remove the ip address from the physical interface
C . create the virtual interfaces with the interface command
D . configure each subinterface with its own IP address
E . disable split horizon to prevent routing loops between the subinterface networks
F . encapsulate the physical interface with multipoint PPP
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You are transferring fuel from the storage tanks to the day tanks by means of an electric fuel oil transfer pumpIf the pump motor catches fire, you would FIRST （）.
A . secure the fuel manifold
B . shut off power to the pump
C . shut off the power ventilation
D . spray water on the fire
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You are provisioning an E-1 circuit on an ONS 15454 SNCP configuration and XC-VXL-10G card. How many total ports are used within the Low-Order matrix at the source node？（）
A . 0
B . 1
C . 2
D . 3
E . 5
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To assist separation of low viscosity oils steam coils or electric heaters are fitted （） of the oily water separator.
A . in entrance
B . in exit
C . in the upper part
D . on the outside
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You are provisioning an E-1 circuit on an ONS 15454 MS-SPRing configuration and XC-VXL-10G card. Each VC-12 connection must also terminate via the VC-3 matrix. How many VC-3 ports remain after this circuit is created， assuming no other circuits？（）
A . 92
B . 93
C . 94
D . 95
E . 96
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in the common-emitter circuit with a voltage-divider bias, the ( ) of the Q-point are independent of β
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原文:他们是电器商品的主要出口商。译文:They are ____exports of electric goods.
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原文：他们是电器商品的主要出口商。译文：They are ____exports of electric goods.
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In the city of Harbin, the ice city, fantastic lanterns are carved from large blocks of ice and gorgeously illuminated with colored electric lights.
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In the circuit, if we take c as the reference ground, and are:/ananas/latex/p/113069
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There are two powerful techniques of circuit analysis that aid in the analysis of complex circuit structures: the node-voltage method and the _________ method.
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They are going to have the serviceman ____ an electric fan in the office tomorrow.
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Observe the diagram. RTC is the hub router and RTA and RTB are the spokes. There are no virtual circuits between the spoke locations. What is needed to successfully route traffic to the 11.11.11.0/24 network from RTA？ （）
<img src='https://img2.soutiyun.com/ask/uploadfile/2019-03-27/3b52a384bbee4e7f118247f79e304256.jpg' />
A. The neighbor 10.10.10.1 next - hop - self com mand on RTA
B. Nothing is required. This is the default behavior on this topology
C. The neighbor 10.10.10.1 next - hop - self command on RTB
D. The neighbor 10.10.10.1 next - hop - self command on RTC
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Click the Exhibit button. Within an ONS 15454, you are provisioning a circuit on an unprotected UPSR ring. In the exhibit, which two must you configure？（） （Choose two.)
<img src='https://img2.soutiyun.com/ask/uploadfile/2019-03-27/caeb03f6c8e10f9c4634f3ed4cfba37a.jpg' />
A. revertive
B. circuit type
C. circuit size
D. bidirectional
E. protected drops
F. switch on PDI-P
