Трансформаторы и электроэнергия – проблемы и решения
1. TПервичная обмотка идеального трансформатора подключена к источнику напряжения, а вторичная обмотка — к лампе, как показано ниже.
А. Лампа будет тускнеть, если уменьшить количество первичных петель.
В. Лампа будет светить ярче, если увеличить количество вторичных петель.
C. Лампа будет светить тусклее при повышении первичного напряжения.
D. Лампа будет светлее, если не...основные петли сокращаются
Е. Свет останется тем же, если изменить петли.
Решение
The change in the number of coil loops affects only the type of трансформатор. If the primary loops reduced so that the secondary loops are more then this transformer becomes a step-up transformer that raises the voltage. Likewise, when the coil loops are coupled so that the secondary coil loops is less then this transformer becomes a step-down transformer that lowers the voltage.
Keep in mind that when the power voltage increases, the электрический ток strength decreases so that the электроэнергия is constant (P = V I). Electrical power is the change of электроэнергия over a certain time interval. When the input power is equal to the output power the amount of energy consumed is also the same.
Light or dim light is associated with many or at least electrical energy that is converted into light energy. If a lot of electrical energy is converted into light energy then a bright light, otherwise if a little electrical energy is converted into light energy then the light is dim. The electric power is constant, the electric energy is also constant so the light is the same.
Правильный ответ Е.
2. The image below describes the ideal transformer. The primary coil is connected to a voltage source and the secondary coil is connected to a lamp (L). Then the condition of the lamp will be…
A. Normal brightness when the primary loops are changed
B. Dimmed when primary voltage increased
C. Bright when secondary loops are increased
D. Dimmed when secondary loops are increased
E. Brighter when the primary loops are reduced
решение:
Input power = P = V I = (200 Volt)(2 Ampere) = 400 Watt = Output power
The transformer only reduces the voltage but does not reduce the electrical power. Electric power kept constant therefore when the electric voltage decreases, the electric current increases (P = V I). The input electrical power the same as the output power so that the electrical energy used during a certain time interval is also the same. Thus light is normal or unchanged.
Правильный ответ А.
3.
The secondary coil is connected to a bulb lamp, while the primary coil is connected to a voltage source. The light bulb will turn on …
A. brighter if the number of primary loops is increased
B. brighter if the number of secondary loops is increased
C. brighter if the number of secondary loops is equal to the primary
D. dimmed when the primary voltage is increased
E. dimmed when the primary voltage and the number of secondary loops are increased
Решение
Здесь нет исправить ответ
