Ohms Law Quiz: Master Voltage and Current Concepts

1. Ohm’s law relates voltage (V), current (I), and resistance (R) as:

(v = ir^2)

(v = ir)

(i = vr)

(r = vi^2)

Ohm’s law states voltage equals current times resistance. It describes many simple 'ohmic' conductors where (R) stays constant.

Explanation

Ohm’s law states voltage equals current times resistance. It describes many simple 'ohmic' conductors where (R) stays constant.

2. Current is the rate of flow of electric charge.

True

False

Current measures how much charge passes a point each second. Its unit is the ampere (A).

Explanation

Current measures how much charge passes a point each second. Its unit is the ampere (A).

3. Voltage is best described as:

Charge flow rate

Resistance to current

Energy per charge (electric potential difference)

Heat energy only

Voltage is the energy transferred per unit charge between two points. It 'pushes' charges through a circuit.

Explanation

Voltage is the energy transferred per unit charge between two points. It 'pushes' charges through a circuit.

4. Resistance tells how hard it is for charges to flow through a material or component.

True

False

Higher resistance means less current for the same voltage. It reflects how collisions and material structure hinder charge motion.

Explanation

Higher resistance means less current for the same voltage. It reflects how collisions and material structure hinder charge motion.

5. If (V = 12) V and (R = 6) Ω, the current is:

0.5 A

1 A

2 A

18 A

Rearranging Ohm’s law gives (I = V/R). (12/6 = 2) A.

Explanation

Rearranging Ohm’s law gives (I = V/R). (12/6 = 2) A.

6. If (I = 0.5) A and (V = 10) V, the resistance is:

5 Ω

20 Ω

0.05 Ω

10 Ω

(R = V/I). (R = 10/0.5 = 20) Ω. This shows how small currents can indicate higher resistance at a given voltage.

Explanation

(R = V/I). (R = 10/0.5 = 20) Ω. This shows how small currents can indicate higher resistance at a given voltage.

7. The SI unit of current is:

Volt (V)

Ampere (A)

Ohm (Ω)

Watt (W)

Current is measured in amperes. It is a fundamental electrical quantity in circuits.

Explanation

Current is measured in amperes. It is a fundamental electrical quantity in circuits.

8. If resistance increases while voltage stays the same, current decreases.

True

False

From (I = V/R), larger (R) gives smaller (I). This is why resistors can limit current.

Explanation

From (I = V/R), larger (R) gives smaller (I). This is why resistors can limit current.

9. If current doubles in an ohmic resistor while resistance stays constant, voltage across it:

Halves

Doubles

Stays the same

Becomes zero

With constant (R), (V=IR) shows (V) is directly proportional to (I). Doubling (I) doubles (V).

Explanation

With constant (R), (V=IR) shows (V) is directly proportional to (I). Doubling (I) doubles (V).

10. A voltmeter is connected in parallel across a component.

True

False

Voltage is a potential difference between two points, so the voltmeter must connect across those points. It typically has high resistance.

Explanation

Voltage is a potential difference between two points, so the voltmeter must connect across those points. It typically has high resistance.

11. Ohm’s law works for many resistors, but not for every electrical component.

True

False

Components like diodes and lamps may change resistance with voltage or temperature. Ohm’s law in its simplest form assumes constant resistance.

Explanation

Components like diodes and lamps may change resistance with voltage or temperature. Ohm’s law in its simplest form assumes constant resistance.

12. A higher voltage across the same resistor usually results in a higher current.

True

False

(I ∝ V) for constant (R). For an ohmic resistor, current increases in direct proportion to voltage. This is the straight-line I–V behavior.

Explanation

(I ∝ V) for constant (R). For an ohmic resistor, current increases in direct proportion to voltage. This is the straight-line I–V behavior.

13. Current in a circuit is measured in coulombs.

True

False

Charge is measured in coulombs (C). Current is charge per second, measured in amperes (A).

Explanation

Charge is measured in coulombs (C). Current is charge per second, measured in amperes (A).

14. The unit of resistance is the ______ (Ω).

Resistance measures how strongly a component opposes current. The ohm is defined so that 1 Ω = 1 V/A.

Explanation

Resistance measures how strongly a component opposes current. The ohm is defined so that 1 Ω = 1 V/A.

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15. The best overall summary is:

(V) is always equal to (I+R)

Ohm’s law (V=IR) links voltage, current, and resistance for many conductors with constant resistance

Voltage measures charge flow rate

Resistance is measured in volts

Ohm’s law describes linear behavior where resistance stays constant. It is a key tool for analyzing basic circuits.

Explanation

Ohm’s law describes linear behavior where resistance stays constant. It is a key tool for analyzing basic circuits.

16. A device used to measure current is an ______.

An ammeter is connected in series so the same current passes through it. It is designed to have low resistance.

Explanation

An ammeter is connected in series so the same current passes through it. It is designed to have low resistance.

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17. The unit 'volt per ampere' is equal to:

Watt

Ohm

Coulomb

Tesla

From (R = V/I), resistance has units V/A. This defines the ohm.

Explanation

From (R = V/I), resistance has units V/A. This defines the ohm.

18. Which device is typically non-ohmic?

A fixed metal resistor

A diode

A wire at constant temperature

A precision resistor

Diodes have a non-linear I–V relationship. Their 'resistance' changes strongly with voltage direction and magnitude.

Explanation

Diodes have a non-linear I–V relationship. Their 'resistance' changes strongly with voltage direction and magnitude.

19. Rearranging (V=IR) for resistance gives (R = ______).

Resistance can be found by dividing voltage by current. This is often used when measuring unknown resistors.

Explanation

Resistance can be found by dividing voltage by current. This is often used when measuring unknown resistors.

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20. The unit symbol for resistance is ______.

The ohm symbol is the Greek letter omega. It is used on circuit diagrams and component labels.

Explanation

The ohm symbol is the Greek letter omega. It is used on circuit diagrams and component labels.

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Ohms Law Quiz: Test Your Understanding of Voltage And Current

1. Ohm’s law relates voltage (V), current (I), and resistance (R) as:

2.

What first name or nickname would you like us to use?

2. Current is the rate of flow of electric charge.

3. Voltage is best described as:

4. Resistance tells how hard it is for charges to flow through a material or component.

5. If (V = 12) V and (R = 6) Ω, the current is:

6. If (I = 0.5) A and (V = 10) V, the resistance is:

7. The SI unit of current is:

8. If resistance increases while voltage stays the same, current decreases.

9. If current doubles in an ohmic resistor while resistance stays constant, voltage across it:

10. A voltmeter is connected in parallel across a component.

11. Ohm’s law works for many resistors, but not for every electrical component.

12. A higher voltage across the same resistor usually results in a higher current.

13. Current in a circuit is measured in coulombs.

14. The unit of resistance is the ______ (Ω).

15. The best overall summary is:

16. A device used to measure current is an ______.

17. The unit 'volt per ampere' is equal to:

18. Which device is typically non-ohmic?

19. Rearranging (V=IR) for resistance gives (R = ______).

20. The unit symbol for resistance is ______.