Quiz về Điện Thế

What is the unit of electric potential?

• Volt (V)

• Joule (J)

• Volt per meter (V/m)

• Watt (W)

The electric potential at a point M in an electric field E does not depend on

• the position of point M

• the intensity of the electric field E

• the charge q placed at point M

• the reference point chosen for electric potential

Given that the electric potential at point M in the Earth's uniform electric field is 120 V. The reference potential is chosen at the ground. The electron placed at point M has potential energy of:

When we negatively charge a spherical iron ball, the electrons repel each other and distribute themselves outside the ball. The core of the ball is completely neutral. For such a negatively charged iron ball:

• The core has a higher electric potential than the outer layer.

• The outer layer has a higher electric potential than the core.

• The electric potential of every point in the ball is the same.

• A and C can both be true.

At a place where the Earth's electric field is 115 V/m, two parallel plates are placed parallel to the ground. The first plate is 1 m above the ground and is connected to the ground by a copper wire. The second plate is 1.073 m above the ground and is positively charged. The measured potential difference between the two plates is 1.5 V. Choosing the ground as the reference potential, the potential of the positively charged plate is

• 1.5 V

• 8.39 V

• 0 V

• -8.39 V

Which of the following conclusions is correct regarding the function of a power source?

• to create and maintain electric potential to sustain current in the circuit.

• to create negative ions.

• to create positive ions.

• to create negative ions flowing in the conductor.

Which of the following conclusions is incorrect regarding the electromotive force of a power source?

Which conclusion is incorrect regarding the electromotive force of a power source?

• The electromotive force of a power source characterizes its ability to do work.

• The electromotive force of a power source is measured by the ratio Aq.

• The unit of electromotive force is volt (V).

• The electromotive force of a power source characterizes its ability to accumulate charge.

The expression for the work of a power source with a constant current is

• A= UIt.

• A = Eit

• EIt-rI2t.

• EIt+rI2t.

Which statement about power sources is incorrect?

• Each source has two terminals that are always in different charged states.

• A power source is a mechanism to create and maintain voltage to sustain current in a circuit.

• To create charged terminals, a force must do work to separate and move electrons or positive ions away from the electrodes, this force is called a strange force.

• A power source is a battery with a strange force being electrostatic force.