更多"A resistance in a circuit of unknow"的相关试题:
[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
[单项选择]In a series circuit, which value will remain unchanged at all places in the circuit?（）
A. Voltage
B. Current
C. Resistance
D. Inductance
[单项选择]The total resistance of a parallel circuit is always （）.
A. larger than the greatest branch resistance
B. smaller than the lowest branch resistance
C. equal to the sum of the individual branch resistances
D. one-half the sum of the individual branch resistances
[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
[简答题]GIS就地控制屏上发“跳闸回路A/B闭锁（TRIP CIRCUIT A/B BLOCKED）”报警的原因有哪些？
[单项选择]The correct pH value of boiler water is achieved by continuous addition of a suitable （） to the feed.
A. acid
B. alkali
C. salt
D. None of the above
[名词解释]SELV回路（SELV circuit）
[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]Capacitance is the property of an electric circuit opposing a change in the （）
A. current in the circuit
B. voltage in the circuit
C. inductance in the circuit
D. resistance in the circuit
[单项选择]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
[单项选择]The purpose of a main switchboard circuit breakers reverse-power trip is to （）.
A. prevent main circuit overload
B. protect the circuit breaker blowout coil
C. prevent alternator motorization
D. prevent low voltage tripout
[名词解释]边际产值 marginal value
[单项选择]With a purely resistance load the voltage and current are in phase, giving a power factor of （）.
A. one
B. less than one
C. more than one
D. negative one
[单项选择]The centre of lateral resistance is（）.
A. the center of the hydrodynamic forces acting on the underwater hull to resist the effect of the wind
B. the point of influence of wind on the ship
C. the pivot point
D. the point on the ship's above-water structure upon which the whole force of the wind can be considered an act
[单项选择]The resistance of electric wire will decrease as its （）
A. length increases
B. cross-sectional area increases
C. temperature increases
D. percent of metallic purities increases
[单项选择]An accidental path of low resistance, allowing passage of abnormal amount of current is known as a/an（）.
A. open circuit
B. short circuit
C. polarized ground
D. ground reference point
