正在学习
1.6 Electricity Generation
1.6 Electricity Generation
Electricity exists in all matter. However, matter is electrically neutral. Therefore, to establish an electric current some external energy must be applied in order to release some electrons (electrical charge), i.e. to obtain electricity. It can be done by means of using the mechanical energy in turbines, either wind, water, or others attached to synchronous, asynchronous, or other electric generators. We can model every device with the lumped circuit abstraction like the model of the solar cell that harvests the energy contained in sunbeams.
练习题
Why must external energy be applied to matter in order to establish an electric current?
A. Because matter is electrically neutral and electrons must be released
B. Because matter contains no electrons in its natural state
C. Because all materials are perfect insulators
D. Because electrons are permanently bound to all atomic nuclei
Which types of electric generators are mentioned as being attached to turbines for electricity generation?
A. Only synchronous generators
B. Only asynchronous generators
C. Both synchronous and asynchronous generators
D. Only DC generators
Which of the following are mentioned in the text as sources of mechanical energy that can be used in turbines for electricity generation?
A. Wind
B. Water
C. Nuclear fission
D. Chemical combustion
Which of the following statements about electricity generation are correct according to the text?
A. External energy must be applied to release electrons
B. Mechanical energy in turbines can be used to generate electricity
C. Matter naturally contains an established electric current
D. The lumped circuit abstraction can be used to model devices like solar cells
In its natural state, all matter is electrically neutral.
An electric current can be established spontaneously without any external energy input.
The lumped circuit abstraction can only be applied to model solar cells and cannot be used for other devices.
To obtain electricity, some external ___ must be applied in order to release electrons from matter.
Turbines using wind or water can be attached to synchronous or ___ electric generators to produce electricity.
Explain the relationship between matter's electrical neutrality and the need for external energy to establish an electric current.
How does the atomic structure of conductors (with valence electrons) relate to the requirement for external energy to establish current?
Since matter is electrically neutral, external energy is required to release electrons and establish an electric current. Based on atomic structure, why is copper more suitable than an insulator like glass for this purpose?
A. Copper has complete outer electron shells, making electrons easier to release
B. Copper has incomplete outer electron shells with valence electrons that are easily released
C. Glass has more free electrons than copper, but they require more energy to release
D. Both copper and glass have the same atomic structure, but copper conducts heat better
When mechanical energy from a wind turbine is used to generate electricity, the resulting electron flow in a copper wire moves in the same direction as the conventional current.
Which of the following statements correctly describe the relationship between external energy, electron behavior, and electric current generation? Select all that apply.
A. External energy is needed to release electrons because matter is electrically neutral
B. Free electrons in conductors move between adjacent atoms even without external energy
C. When an atom loses an electron due to external energy, it becomes a positive ion
D. Insulators require no external energy to establish current because they have tightly held electrons
E. Mechanical energy in turbines can provide the external energy needed to establish electron flow
When external energy is applied to a copper conductor, atoms lose electrons and become ___ ions, which then attract electrons to establish an electron flow.
Explain why silver, copper, gold, and aluminum are preferred materials for wires in electric generators that convert mechanical energy to electricity.
登录后解锁笔记、知识点解析、AI 问答
立即登录