Quiz
Know the effects of components
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Perguntas do quiz (20)
1Which of the following formulas can calculate power in an ac circuit?
- AP = V x I x pf
- BP = V + I
- CP = V x I
- DP = V/R
2What is the power produced by a 400v three phase system which delivers 25A at a power factor of 0.85
- A14.72kW
- B6.23kW
- C10kW
- D14kW
- A14.72kW
3What is the power produced by a 400v three phase system which delivers 10A at a power factor of 0.7
- A4849.6W
- B4.7kW
- C5000W
- D4700W
4The power factor of an installation can be calculated from
- ACosθ = Z/X
- BCosθ = X/Z
- CCosθ = KVA/KW
- DCosθ = KW/KVA
5The power factor of an inductive load can be improved by?
- AConnecting a inductor across the load
- BConnecting a resistor in parallel with the load
- CConnecting a capacitor in series with the load
- DConnecting a capacitor across the load (parallel)
6The power factor of a load consisting of inductance and resistance can be calculated from
- ACosθ = True Power/Apparent Power
- BCosθ = Apparent Power/ Reactive Power
- CCosθ = Reactive Power/True Power
- DCosθ = Apparent Power/True Power
7The formula required to calculate the total power of a single phase inductive load supplied by an a.c. supply is
- AP = IV sinθ
- BP = IV
- CP = IV tanθ
- DP = IV cosθ
8If the W is 100 and the VA is 120 what would the power factor be
- A0.75
- B0.2
- C0.85
- D0.83
9If the kW is 200 and the KVA is 400 what would the power factor be?
- A0.6
- B0.7
- C0.8
- D0.5
10A single phase circuit draws a current of 21.7A from a 230 V circuit at a power factor of 0.4
What is the current drawn if the power factor is corrected to 0.85- A18.4 A
- B23.4 A
- C10.21 A
- D21.7 A
11A circuit dissipates 2000 W at a power factor of 0.5 when connected to a 230 V ac supply. The current drawn from the supply is
- A17.8 A
- B17.39 A
- C4.3 A
- D8.7 A
12A circuit dissipates 1.5 kW at a power factor of 0.75 when connected to a 230V ac supply. The current drawn from the supply is
- A7.8 A
- B9.2 A
- C6.5 A
- D8.7 A
13A three phase system gives the following readings
kVA =30 kW= 45
What is the power factor for the system- A0.67
- Bunity
- C1.5
- D0.8
14A three phase system gives the following readings
kW= 400 kVA = 500
What is the power factor for the system- A1.25
- Bunity
- C0.8
- D0.6
15What unit is reactive power measured in
- AkA
- BKVAr
- CkW
- DKVA
16What unit is apparent power measured in
- AkA
- BKVAr
- CkW
- DKVA
17What unit is true power measured in
- AKVAr
- BkA
- CkW
- DKVA
18Which component would cause the current and voltage to behave as above
- Aresistor
- Brectifier
- Ccapacitor
- DInductor
19Which component would cause the current and voltage to behave as above
- AInductor
- Bcapacitor
- Cresistor
- Drectifier
20Which component would cause the current and voltage to behave as above
- AInductor
- Bcapacitor
- Cresistor
- Drectifier
Informações
- Descrição
- Leading and lagging circuits
- Autor
- Vito Martino
- Idioma
- English
- Visualizações
- 834
- Etiquetas
- Avaliação
- 4,0 de 5 · 1 avaliação Avalie este quiz