Ohm's Law

Description: Ohm's Law Quiz: Test Your Understanding of Electrical Circuits
Number of Questions: 15
Created by:
Tags: ohm's law electrical circuits voltage current resistance
Attempted 0/15 Correct 0 Score 0

Ohm's Law states that the current (I) flowing through a conductor is directly proportional to the voltage (V) applied across it, provided the temperature and other physical conditions remain constant. Mathematically, it can be expressed as:

  1. I = V / R

  2. I = R / V

  3. V = I * R

  4. V = R / I


Correct Option: A
Explanation:

Ohm's Law is a fundamental relationship in electrical circuits, where the current through a conductor is directly proportional to the voltage applied across it, with the proportionality constant being the resistance of the conductor.

The unit of resistance in the International System of Units (SI) is:

  1. Ohm (Ω)

  2. Volt (V)

  3. Ampere (A)

  4. Watt (W)


Correct Option: A
Explanation:

The unit of resistance in the SI system is the Ohm (Ω), named after the German physicist Georg Ohm. It represents the resistance offered by a conductor to the flow of electric current.

In a circuit, if the voltage across a resistor is doubled while the resistance remains constant, the current through the resistor will:

  1. Double

  2. Halve

  3. Remain the same

  4. Increase four times


Correct Option: A
Explanation:

According to Ohm's Law, the current through a conductor is directly proportional to the voltage applied across it. Therefore, if the voltage is doubled while the resistance remains constant, the current will also double.

If the resistance of a conductor is increased while the voltage remains constant, the current through the conductor will:

  1. Increase

  2. Decrease

  3. Remain the same

  4. Become zero


Correct Option: B
Explanation:

Ohm's Law states that the current through a conductor is inversely proportional to the resistance. Therefore, if the resistance is increased while the voltage remains constant, the current will decrease.

A resistor with a resistance of 10 ohms is connected to a battery with a voltage of 12 volts. What is the current flowing through the resistor?

  1. 1.2 Amperes

  2. 2.4 Amperes

  3. 0.83 Amperes

  4. 1.5 Amperes


Correct Option: A
Explanation:

Using Ohm's Law (I = V / R), we can calculate the current: I = 12 V / 10 Ω = 1.2 A.

In a series circuit, the total resistance is:

  1. The sum of the individual resistances

  2. The average of the individual resistances

  3. The product of the individual resistances

  4. The reciprocal of the sum of the individual resistances


Correct Option: A
Explanation:

In a series circuit, the total resistance is the sum of the individual resistances of the components connected in series.

In a parallel circuit, the total resistance is:

  1. The sum of the individual resistances

  2. The average of the individual resistances

  3. The product of the individual resistances

  4. The reciprocal of the sum of the individual resistances


Correct Option: D
Explanation:

In a parallel circuit, the total resistance is the reciprocal of the sum of the individual resistances of the components connected in parallel.

The power dissipated in a resistor is given by:

  1. P = I^2 * R

  2. P = V^2 / R

  3. P = V * I

  4. P = I / R


Correct Option: A
Explanation:

The power dissipated in a resistor is given by the formula P = I^2 * R, where P is the power in watts, I is the current in amperes, and R is the resistance in ohms.

A light bulb with a resistance of 100 ohms is connected to a 120-volt outlet. What is the power consumed by the light bulb?

  1. 144 watts

  2. 120 watts

  3. 240 watts

  4. 180 watts


Correct Option: A
Explanation:

Using the formula P = V^2 / R, we can calculate the power: P = (120 V)^2 / 100 Ω = 144 W.

The resistance of a conductor is temperature-dependent. As the temperature increases, the resistance of most conductors:

  1. Increases

  2. Decreases

  3. Remains the same

  4. Becomes zero


Correct Option: A
Explanation:

For most conductors, the resistance increases as the temperature increases. This is because the increased thermal energy causes the atoms in the conductor to vibrate more, which hinders the flow of electrons.

Superconductors are materials that exhibit:

  1. Zero resistance

  2. Infinite resistance

  3. Negative resistance

  4. Variable resistance


Correct Option: A
Explanation:

Superconductors are materials that exhibit zero resistance, meaning they allow electric current to flow through them without any energy loss.

The phenomenon of superconductivity was first discovered by:

  1. Georg Ohm

  2. Albert Einstein

  3. James Clerk Maxwell

  4. Heike Kamerlingh Onnes


Correct Option: D
Explanation:

Heike Kamerlingh Onnes, a Dutch physicist, first discovered superconductivity in 1911 while studying the electrical resistance of mercury at very low temperatures.

Superconductivity is a:

  1. Classical phenomenon

  2. Quantum phenomenon

  3. Electromagnetic phenomenon

  4. Mechanical phenomenon


Correct Option: B
Explanation:

Superconductivity is a quantum phenomenon that occurs at very low temperatures, typically near absolute zero (-273.15 °C or -459.67 °F).

Superconductors have a wide range of applications, including:

  1. Power transmission

  2. Medical imaging

  3. Magnetic levitation trains

  4. All of the above


Correct Option: D
Explanation:

Superconductors have a wide range of applications, including power transmission with reduced losses, medical imaging (MRI), and magnetic levitation trains (maglev).

The critical temperature (Tc) of a superconductor is the temperature above which it loses its superconducting properties and starts behaving like a normal conductor.

  1. True

  2. False


Correct Option: A
Explanation:

The critical temperature (Tc) of a superconductor is the temperature above which it loses its superconducting properties and starts behaving like a normal conductor.

- Hide questions