更多"The total resistance of a parallel "的相关试题:
[单项选择]The total power consumed in a parallel circuit is （）
A. the sum of the powers used in each load (resistor)
B. divided by the number of loads
C. always less than the power used in the smallest load
D. the sum of the powers used in each individual load never more than the power used in the largest load
[单项选择]If the resistance of a circuit is cut in half and the applied voltage is kept constant, the current flow will be （）.
A. doubled
B. quadrupled
C. unchanged
D. cut in half
[单项选择]A resistance in a circuit of unknown value is to be tested using the voltmeter/ammeter methodTherefore, the meters should be connected with（）.
A. both meters in series with the resistance
B. both meters in parallel with the resistance
C. the ammeter in series and the voltmeter in parallel with the resistance
D. the ammeter in parallel and the voltmeter in series with the resistance
[名词解释]SELV回路（SELV circuit）
[单项选择]The division of kilowatt load between two paralleled alternators is determined by the （）
A. amount of field excitation of the leading machine
B. load-speed characteristics of the governors
C. amount of field excitation to the lagging machine
D. type of alternator
[单项选择]The distance a vessel moves parallel to the original course from the point where the rudder is put over to any point on the turning circle is called the（）.
A. advance
B. drift angle
C. pivoting point
D. transfer
[单项选择]When carrying out a parallel track search pattern，the course of the search units should normally be which of the following?（）
A. In the same direction as the anticipated drift
B. In the opposite direction of the anticipated drift
C. Perpendicular to the line of anticipated drift
D. Downwind
[单项选择]You are attempting to parallel two AC generators, and the syncope pointer is revolving in the fast directionThis indicates that the frequency of the incoming machine is （）.
A. higher than the bus frequency
B. lower than the bus frequency
C. the same as the bus frequency but out of phase with it
D. the same as the bus frequency and the circuit breaker may be closed at any pointer position
[单项选择]You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow directionThis indicates that the frequency of the incoming machine is （）.
A. higher than the bus frequency
B. lower than the bus freouencv
C. the same as the bus frequency but out of phase with it
D. the same as the bus frequency, and the circuit breaker may be closed at any pointer position
[单项选择]The broken magenta line which runs parallel to the shorebetween Roanoke Point and Mattituck Inlet marks a（）.
A. fish trap area
B. pipeline
C. demarcation line
D. cable area
[单项选择]You are running parallel to the coast and estimate that the current is against you.In plotting a running fix using bearings from the same object on the coast，the greatest safety margin from inshore dangers will result if what speed is used to determine（）.
A. Minimum speed estimate
B. Maximum speed estimate
C. Average speed estimate
D. A running fix should not be used under these conditions
[单项选择]To parallel an incoming machine to a running machine therefore it is necessary to ensure firstly that （）.
A. two frequencies must be brought into phase
B. the incoming machine accepts a small amount of load
C. the running machine must be unload
D. both voltages are equal
[单项选择]The resistance of a conductor varies （）
A. directly as its length and inversely as its cross-sectional area
B. inversely as its length and directly as its cross-sectional area
C. directly as its length and directly as its cross-sectional area
D. inversely as its length and inversely as its cross-sectional area
[单项选择]Wrought iron has an inherent resistance to corrosion but is not to be had freely , its place has been taken by the cuprous alloysAccording to the above sentence , which of the following statements is true?（）
A. Wrought iron can resist liquids flow
B. It is difficult to attain the wrought iron
C. Wrought iron should be combined with cuprous alloys
D. The cuprous alloys have mere disadvantages than wrought iron
[单项选择]When two DC generators operate in parallel, they are protected against motorizing by（）
A. blow out coils
B. governor relay
C. under voltage trips
D. reverse current trips
[单项选择]If two AC generators are operated in parallel, the load is distributed evenly by（）
A. a rheostat
B. a balancing coil
C. changing field excitation
D. adjusting the governor settings
