An electric field is:

Question

BlackTom AI · Accepted Answer

An electric field is a region of space around a charged object that can exert a force on other charges; this is the core defining concept.

1. Relevant knowledge points and concepts
- Electric field (E) describes how a charge influences space around it.  
- A test charge q placed in that region experiences an electric force F related by E = F/q (vector relation).  
- Field lines show direction (away from positive, toward negative) and relative strength (density of lines).

2. Step-by-step reasoning
- Consider a source charge Q creating an influence in space. That influence is not the force itself but a property of the space: the electric field.  
- Place a small test charge q in the region. Measure the force F on q. The electric field at that point is defined as E = F/q, so the field determines the force per unit charge.  
- Therefore the electric field is best described as the area/region around a charged object that exerts electric forces on other charges.

3. Calculations (intermediate steps)
- If Coulomb’s law gives F = k Q q / r^2, then E = F/q = k Q / r^2. This shows the field depends on source charge Q and distance r, not on the test charge q.

4. Why the correct answer is correct
- Option d explicitly states that an electric field is an area (region) around a charged object that exerts an electric force on other charged objects, matching the formal definition E = F/q and the conceptual meaning of field lines and force-per-unit-charge.

5. Why other options are incorrect
- a: Describes electric force (attraction/repulsion) between charges, not the field itself.  
- b: Too vague—“interaction” doesn’t define the local property (field) or how force per unit charge is described.  
- c: Incorrect statement; electric charges can exist singly (isolated charges) and this option is not a definition of a field.

6. Conclusion
This reasoning confirms the correct answer is d. An electric field is an area around a charged object that exerts an electric force on other charged objects.

An electric field is:单项选择题

类似问题

The potential difference between the plates of a parallel plate capacitor with the plate separation of 6 cm is 60 V. What is the electric field between the plates of this capacitor?

Calculate the electric field strength when a force of 4.0 × 10-9 𝑁 acts on a charge of 8.5 × 10-6𝐶.

Which, among the following is the correct expression for an electric field?

The potential at x = 8 m is -2000 V and at x = 2 m is +400 V. What is the magnitude and direction of the electric field?

Two point charges are placed along a horizontal axis with the following values and positions: +3.0 µC at x = 0 cm and -6.0 µC at x = 20 cm. At what point along the x axis is the electric field zero?

The average distance of the electron from the proton in the hydrogen atom is 0.51 x 10-10 m. What is the electric field from the proton’s charge at the location of the electron? (ke = 8.99 x 109 N×m2/C2, elementary charge e = 1.6 x 10-19 C)

Consider the following diagram. Two parallel plates are separated in vacuum by 0.200 m. The top plate has a potential of 400 V and the bottom plate has a potential of −600 V. An alpha particle is released from the top plate.The acceleration of the alpha particle between the plates is

The electric potential at x = 8 m is −2000 V and at x = 2 m is +400 V. What is the magnitude and direction of the electric field?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单