A: stream
B: wire
C: terminal
D: light
举一反三
- An electric current is the flow of ___________. A: sort B: stream C: energy electrons D: electrons
- Power supply, the conductor, the control device and ______ are four basic parts of an electric circuit
- If _____ voltage is applied across _____ circuit, _____ electric current will flow in _____ circuit.
- If _____ voltage is applied across circuit, electric current will flow in circuit. A: a B: an C: the D: 不填冠词
- The plus (+) and minus (-) signs in an electric circuit diagram are used to define . A: . voltage polarity B: . current direction C: . power flow D: . absorbed power
内容
- 0
Which of the following statements about a conductor in the static case is not true导体在静电平衡下表述不正确的是 A: The conductor must be at the same electric potential B: The surface of the conductor is an equi-potential surface等势面 C: There can be an electric field within the conductor导体内 D: There can be no net charge within the conductor体内无净电荷
- 1
On the ideal conductor surface, the relationship between the electric field lines and the conductor surface is A: the electric field lines is always pertendicular to the conductor surface. B: the electric field lines is always parallel to the conductor surface. C: there is no electri field lines exsited. D: unable to determine the relationship.
- 2
4-3。What is the working principle for LED？（ ） A: convert electric to light B: convert light to electric C: convert electric to heat
- 3
On the surface of a perfect conductor, the normal component of the electric displacement vector is A: continuous with the normal component of the electric displacement vector inside the conductor B: uncertain C: equal to the surface density of free charge on the conductor surface. D: equal to zero
- 4
The fundamental principle in accordance with which all energy transformation in an electric circuit takes place has been already discussed.