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Instructions – Questions on this test are taken from the two texts below. Read them carefully and then choose the correct alternatives that answer the questions or complete the statements placed immediately after each of them.
TEXT ONE
Wind Power
Wind power exploits the kinetic energy of wind in wind turbines to generate other forms of power, especially mechanical power and electricity. It is considered one of the most used forms of renewable energies: the term wind power describes the power generated from no-fossil sources, whose use has a very significant environmental importance by assuring both minor air pollution and reduction of gas carbon emission rate. Another positive aspect related to its use is the exceptional cost/production ratio.
Wind and Aeolic Generators
Air generators, the technical name for pinwheel, divide into various categories according to: the Aeolian generator that can be either on horizontal or on vertical axis, the number of shovels (from one to three) and the lengths of shovels (from fifty centimetres to thirty meters).
Air generators are constituted by: a rotor (a pivot on which are inserted shovels), a stopping system for shovels block; a turns’ multiplier to increase shovels’ speed, a generator that enables to convert mechanical power into electricity; and a control system that manages the pinwheel functionality (and that, in overloaded or malfunctioning eventuality, blocks it); some air generators, generally the bigger ones, have also a system that provides a constant alignment between the rotor axis and the wind direction.
Wind Farms
The “Wind Farms” are real power stations: they originate from the connection of several air generators located within a fixed distance from each other in order to avoid dangerous interferences among them.
Some Wind Farms, named Off-Shore, are located into the sea, near coasts and lakes; they are a valuable option also in densely populated countries.
The history of wind plants in Italy is almost recent; the first air generator, installed in Sardinia, dates back to 1989; up to now we can say that the wind power use is considerably increased: the number of wind plants is raised up to around forty.
Air Generators
Anyway, it is of note that this form of energy has some negative aspects: from an environmental point of view, even if they reduce the gas emissions rates, they have a negative landscape/visual impact. In addition, because air generators are fairly noisy, the noise pollution can annoy persons and animals that take also other risks: birds can be killed while flying across shoves, even if this rarely happens; there is also the problem of interferences, and of the magnetic fields creation, but this can be avoided by using small expedients.
To finish with, it is worth saying that wind power considerably reduces both gas and polluters emissions, which is on the contrary avoidable from normal power stations.
http://www.rheonetic.com/wind-power/wind-power/
Instructions – Questions on this test are taken from the two texts below. Read them carefully and then choose the correct alternatives that answer the questions or complete the statements placed immediately after each of them.
TEXT ONE
Wind Power
Wind power exploits the kinetic energy of wind in wind turbines to generate other forms of power, especially mechanical power and electricity. It is considered one of the most used forms of renewable energies: the term wind power describes the power generated from no-fossil sources, whose use has a very significant environmental importance by assuring both minor air pollution and reduction of gas carbon emission rate. Another positive aspect related to its use is the exceptional cost/production ratio.
Wind and Aeolic Generators
Air generators, the technical name for pinwheel, divide into various categories according to: the Aeolian generator that can be either on horizontal or on vertical axis, the number of shovels (from one to three) and the lengths of shovels (from fifty centimetres to thirty meters).
Air generators are constituted by: a rotor (a pivot on which are inserted shovels), a stopping system for shovels block; a turns’ multiplier to increase shovels’ speed, a generator that enables to convert mechanical power into electricity; and a control system that manages the pinwheel functionality (and that, in overloaded or malfunctioning eventuality, blocks it); some air generators, generally the bigger ones, have also a system that provides a constant alignment between the rotor axis and the wind direction.
Wind Farms
The “Wind Farms” are real power stations: they originate from the connection of several air generators located within a fixed distance from each other in order to avoid dangerous interferences among them.
Some Wind Farms, named Off-Shore, are located into the sea, near coasts and lakes; they are a valuable option also in densely populated countries.
The history of wind plants in Italy is almost recent; the first air generator, installed in Sardinia, dates back to 1989; up to now we can say that the wind power use is considerably increased: the number of wind plants is raised up to around forty.
Air Generators
Anyway, it is of note that this form of energy has some negative aspects: from an environmental point of view, even if they reduce the gas emissions rates, they have a negative landscape/visual impact. In addition, because air generators are fairly noisy, the noise pollution can annoy persons and animals that take also other risks: birds can be killed while flying across shoves, even if this rarely happens; there is also the problem of interferences, and of the magnetic fields creation, but this can be avoided by using small expedients.
To finish with, it is worth saying that wind power considerably reduces both gas and polluters emissions, which is on the contrary avoidable from normal power stations.
http://www.rheonetic.com/wind-power/wind-power/
“Mas de detalhe em detalhe [...] chega-se ao apocalipse.” (linhas 42 e 43)
No texto, a conjunção acima sublinhada confere à relação entre os períodos que liga um sentido de
“As abelhas [...] morrem com os pesticidas.” (linhas 32 e 33)
A expressão sublinhada nessa frase tem sentido de
“Os pássaros perderam o seu norte.” (linha 32)
A expressão sublinhada nessa frase pode ser corretamente analisada como
“Os ursos e focas estão em pânico.” (linhas 30 e 31)
A expressão sublinhada nessa frase revela
“Os corais que mantêm a vida e o oxigênio nas águas estão fenecendo.” (linhas 29)
A acentuação colocada na palavra acima sublinhada tem como justificativa
“Mas os comandantes estão discutindo cordialmente [...].” (linhas 33)
A frase transcrita do texto explicita, em relação à situação do planeta Terra, uma
Numere a COLUNA II de acordo com a COLUNA I associando corretamente as maneiras de ligar os grupos de bobinas entre si para formar os enrolamentos nas máquinas elétricas rotativas.
COLUNA I
1. Máquinas de indução
2. Máquinas de corrente contínua
3. Geradores síncronos
COLUNA II
( ) Girando um campo magnético constante (ímã permanente ou criado por corrente contínua) de forma que as linhas de força do campo enlacem as bobinas. O enrolamento se encontra montado na parte fixa da máquina, e o fluxo magnético é criado na parte rotativa.
( ) A armadura e o enrolamento giram, enquanto o campo magnético constante produzido por ímã permanente ou por corrente contínua é montado na parte fixa da máquina. O enrolamento da armadura é enlaçado no seu movimento rotativo pelas linhas de força do fluxo magnético.
( ) O enrolamento da armadura está montado no estator e é alimentado por corrente alternada capaz de criar um campo girante no espaço. O fluxo desse campo enlaça o enrolamento montado no rotor nele induzindo tensões e correntes.
Assinale a alternativa que apresenta a sequência de números CORRETA.
Numere a COLUNA II de acordo com a COLUNA I associando corretamente as leis fundamentais da eletricidade e do magnetismo com sua definição.
COLUNA I
1. Kirchhoff.
2. Biot-Savart.
3. Lenz- Faraday.
4. Ampère.
COLUNA II
( ) Lei da indução eletromagnética.
( ) Lei do circuito elétrico.
( ) Lei circuital do campo magnético.
( ) Lei da força atuante sobre um condutor em um campo magnético
Assinale a alternativa que apresenta a sequência de números CORRETA.
Os sistemas de aterramento devem ser realizados de modo a garantir a melhor ligação com a terra.
Dentre os sistemas de aterramento relacionados, o mais eficiente é o de
Considere uma linha de transmissão com impedância característica igual a 72 Ω ligada a uma carga de 50 Ω.
Nesse caso, o módulo do coeficiente de reflexão será igual a
Circuitos contendo indutores e capacitores em série podem exibir o fenômeno da ressonância.
Nesse caso, na condição de ressonância, está INCORRETO afirmar que a
Em circuitos de controle de acionamento de cargas, diversos tipos de relés são utilizados com funções distintas.
O relé de sequência de fase é mais bem aplicado
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