Electric Potential Quiz: Master Voltage Concepts

1. Voltage is the same thing as current.

True

False

Voltage is energy per charge, while current is charge per time. They are related but different physical quantities.

Explanation

Voltage is energy per charge, while current is charge per time. They are related but different physical quantities.

2. A battery can have voltage even if no current is flowing (open circuit).

True

False

A battery maintains a potential difference by separating charge. Current flows only when there is a closed path.

Explanation

A battery maintains a potential difference by separating charge. Current flows only when there is a closed path.

3. Which statement is most accurate?

Voltage is energy per unit time

Voltage is energy per unit charge

Voltage is charge per unit time

Voltage is force per unit area

Voltage links to energy and charge, not time. This is why it’s measured in joules per coulomb.

Explanation

Voltage links to energy and charge, not time. This is why it’s measured in joules per coulomb.

4. A charge moving “downhill” in electric potential releases electrical potential energy.

True

False

Moving to lower potential can reduce potential energy for a positive charge. That energy can be transferred to other forms (heat, light, motion).

Explanation

Moving to lower potential can reduce potential energy for a positive charge. That energy can be transferred to other forms (heat, light, motion).

5. Potential difference depends on the two points chosen, not on a single point alone.

True

False

Voltage is defined between two points. You can assign a reference “zero,” but only differences are physically measurable.

Explanation

Voltage is defined between two points. You can assign a reference “zero,” but only differences are physically measurable.

6. A potential difference of 0 v between two points means:

No charges exist

No net energy change per charge moving between them

Infinite current flows

The resistance is zero

If the potential difference is zero, a charge does not gain or lose electric potential energy moving between those points. That typically means no driving “push.”

Explanation

If the potential difference is zero, a charge does not gain or lose electric potential energy moving between those points. That typically means no driving “push.”

7. Electric potential (voltage) is best described as:

Charge per second

Energy per unit charge

Force per unit mass

Power per unit time

Voltage tells you how much energy each coulomb of charge can gain or lose. It’s a “per-charge” energy measure, not a force by itself.

Explanation

Voltage tells you how much energy each coulomb of charge can gain or lose. It’s a “per-charge” energy measure, not a force by itself.

8. If voltage is energy per charge, then energy equals voltage times ______.

Multiply both sides by (q) to get (e=vq). This is a common way to compute energy transfer.

Explanation

Multiply both sides by (q) to get (e=vq). This is a common way to compute energy transfer.

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9. The SI unit of electric potential is:

Coulomb (c)

Ampere (a)

Volt (v)

Watt (w)

Electric potential difference is measured in volts. It’s a derived unit equal to j/c.

Explanation

Electric potential difference is measured in volts. It’s a derived unit equal to j/c.

10. Charges “flow” in a circuit because there is a potential difference.

True

False

A potential difference provides an energy difference that pushes charges around the circuit. Without a potential difference, there’s no sustained current in a simple circuit.

Explanation

A potential difference provides an energy difference that pushes charges around the circuit. Without a potential difference, there’s no sustained current in a simple circuit.

11. Higher voltage means more energy transferred per coulomb of charge.

True

False

Since (v = e/q), increasing (v) increases energy per unit charge. This often corresponds to a stronger “push” for charge flow.

Explanation

Since (v = e/q), increasing (v) increases energy per unit charge. This often corresponds to a stronger “push” for charge flow.

12. If a 9 v battery moves 2 c of charge through a circuit, the energy transferred is:

4.5 j

9 j

18 j

90 j

Use (e = vq). With (v=9) and (q=2), (e=18) j.

Explanation

Use (e = vq). With (v=9) and (q=2), (e=18) j.

13. Electric potential difference is commonly called ______.

“Voltage” is the everyday name for potential difference. It describes the difference in electric potential between two points.

Explanation

“Voltage” is the everyday name for potential difference. It describes the difference in electric potential between two points.

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14. 1 volt equals 1 joule per coulomb (1 v = 1 j/c).

True

False

Voltage measures energy divided by charge. That’s why its unit can be written j/c.

Explanation

Voltage measures energy divided by charge. That’s why its unit can be written j/c.

15. Electric potential is most closely analogous to:

Mass

Height in a gravitational field

Temperature

Density

Like height gives gravitational potential energy per mass, electric potential gives electric potential energy per charge. Differences in potential drive motion/flow.

Explanation

Like height gives gravitational potential energy per mass, electric potential gives electric potential energy per charge. Differences in potential drive motion/flow.

16. If 12 j of energy is transferred to 3 c of charge, the potential difference is:

0.25 v

3 v

4 v

36 v

Divide energy by charge. (v = 12/3 = 4) v.

Explanation

Divide energy by charge. (v = 12/3 = 4) v.

17. A potential difference can be measured using a ______ meter.

Voltmeters measure the potential difference between two points in a circuit. They are connected in parallel across components.

Explanation

Voltmeters measure the potential difference between two points in a circuit. They are connected in parallel across components.

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18. If you connect a voltmeter across a resistor, it measures:

Current through the resistor

Potential difference across the resistor

Power of the resistor directly

Resistance without any math

A voltmeter reads the voltage between its two probes. Across a resistor, that is the voltage drop across the resistor.

Explanation

A voltmeter reads the voltage between its two probes. Across a resistor, that is the voltage drop across the resistor.

19. A battery provides:

A constant current no matter what

A potential difference (voltage) between its terminals

A magnetic field only

Infinite power

A battery sets up a potential difference that can drive charge through a circuit. The current depends on the circuit resistance.

Explanation

A battery sets up a potential difference that can drive charge through a circuit. The current depends on the circuit resistance.

20. In a simple circuit with a battery and bulb, the battery’s role is mainly to:

Provide resistance

Provide potential difference

Provide mass

Provide insulation

The battery separates charge and maintains a potential difference. That energy difference allows the bulb to convert electrical energy into light/heat.

Explanation

The battery separates charge and maintains a potential difference. That energy difference allows the bulb to convert electrical energy into light/heat.