Questões de Concurso Para tecnico em elétrica

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Ano: 2013 Banca: VUNESP Órgão: DCTA Prova: VUNESP - 2013 - CTA - Tecnico em Elétrica |
Q2883754 Inglês

A logic circuit has three boolean inputs and one output named A, B, C and S respectively. The boolean input A is connected to an inverter gate, and its result is submitted to an AND gate, along with the input signal B. The AND gate output is then submitted to an OR gate along with the remaining boolean input C. The output of the OR gate is the resulting signal S.

De acordo com o texto, o circuito lógico possui

Alternativas
Ano: 2013 Banca: VUNESP Órgão: DCTA Prova: VUNESP - 2013 - CTA - Tecnico em Elétrica |
Q2883750 Engenharia Elétrica

A four poles, three-phase, doubly-feed induction motor has its rotor winding terminals left unconnected. A three-phase symmetrical power source, with 220,0 [V] and 60,0 [Hz], is suddenly connected to the machine stator electrical terminals at standstill, resulting in line currents with 5,0 [A] of magnitude, lagging the stator voltages for almost 90,0 degrees in each phase.

O texto ilustra a ligação à rede trifásica de alimentação de uma máquina

Alternativas
Ano: 2013 Banca: VUNESP Órgão: DCTA Prova: VUNESP - 2013 - CTA - Tecnico em Elétrica |
Q2883742 Inglês

A 4 poles pairs synchronous machine operates as a motor inside an industrial electrical network, with nominal frequency of 50,0 [Hz]. The synchronous machine rotor is equipped with short-circuited bars, creating a squirrel-cage auxiliary winding, dedicated for dumping effects during transients and also to allow the startup of the motor, when the machine is directly connected to the mains power source.

É apresentada no texto uma máquina elétrica

Alternativas
Ano: 2013 Banca: VUNESP Órgão: DCTA Prova: VUNESP - 2013 - CTA - Tecnico em Elétrica |
Q2883741 Inglês

A transformer has a primary winding circuit with 200 turns and a secondary winding circuit with 10 turns. In an ideal, lossless, transformer model, the magnetic core permeability is infinite despite the voltages applied to the windings, the two windings are perfectly coupled and there are no internal resistance in the condutors. In such transformer, when a sinusoidal voltage is applied at the secondary winding with an amplitude of 5,0 [V] RMS, the RMS voltage in the primary winding terminals is equal to 100,0 [V].

Com relação a esse texto, assinale a alternative correta.

Alternativas
Ano: 2013 Banca: VUNESP Órgão: DCTA Prova: VUNESP - 2013 - CTA - Tecnico em Elétrica |
Q2883740 Inglês

In an experiment, two point charges Q1 and Q2 were put on a straight line path, at a certain distance from each other. When both Q1 and Q2 are charged with +2,0 [mC] each, the resulting electric field intensity equals zero in the middle point in the line path between Q1 and Q2. This is true since their electric field vectors in this position have the same magnitude but opposite directions.

Com relação a esse texto, assinale a alternativa correta.

Alternativas
Respostas
1: E
2: A
3: E
4: C
5: A