A: static charge
B: steady current
C: time-varing current
D: the other three answer are all right.
举一反三
- The more rapidly a bar magnet (or other source of magnetic field) approaches a conducting wire loop, the A: greater the current induced in the coil. B: lower the current induced in the coil. C: greater the resistance of the coil. D: lower the resistance of the coil.
- There is no magnetic field in an ideal conductor, but there is a magnetic field inside because of the surface current。
- What creates a magnetic field? More than one answer may be correct. ( ) A: a stationary object with electric charge B: a charged capacitor disconnected from a battery and at rest C: a stationary conductor carrying electric current D: a difference in electric potential
- 1. What creates a magnetic field? More than one answer may be correct. A: a stationary object with electric charge B: a stationary conductor carrying electric current C: a difference in electric potential D: a charged capacitor disconnected from a battery and at rest
- There is no magnetic field in an ideal conductor, but there is a magnetic field inside because of the surface current。 A: 正确 B: 错误
内容
- 0
The Biot-Savart Law is used to（ ） A: determine the magnetic field created by an electric current B: determine the electric field created by an electric current C: determine the force field created by an electric current D: determine the magnetic field created by individual point charges E: determine the electric field created by individual point charges
- 1
What creates a magnetic field? More than one answer may be correct. A: a<br/>stationary object with electric charge B: a stationary conductor carrying electric current C: a<br/>difference in electric potential D: a<br/>charged capacitor disconnected from a battery and at rest
- 2
Semiconductor<br/>with a current is placed in a magnetic field perpendicular to the<br/>current and it induced electric field in the direction. This<br/>phenomenon is known as the ______ .
- 3
To find the right job in a desired field, it is necessary that you ____ what the current trends are.
- 4
The<br/>Biot-Savart Law is used to A: determine<br/>the electric field created by individual point charges B: determine<br/>the electric field created by an electric current C: determine<br/>the magnetic field created by individual point charges D: determine<br/>the magnetic field created by an electric current E: determine<br/>the force field created by an electric current