The question asks for the unit of electric power. We need to recall the definitions and standard units for various electrical quantities to identify the correct option.
C) Watt (W) is the SI unit of electric power. One Watt is equivalent to one Joule per second (\(1 \text{W} = 1 \text{J/s}\)).
Electrical power in a circuit is the product of which two quantities?
Resistance and Current
Voltage and Resistance
Resistance and Power
Voltage and Current
The question asks to identify the two quantities whose product defines electrical power in a circuit. This requires recalling the fundamental formula for electrical power.
Correct Option: D) Voltage and Current
The electrical power (\(P\)) in a circuit is indeed the product of Voltage (\(V\)) and Current (\(I\)). This is a fundamental relationship in electrical engineering, often referred to as Watt's Law.
What is the formula for calculating power in terms of resistance and voltage?
To find the formula for power in terms of resistance and voltage, we start with the basic formula for electrical power and then use Ohm's Law to substitute current in terms of voltage and resistance.
The general formula for electrical power (\(P\)) is the product of voltage (\(V\)) and current (\(I\)).
\[ P = V \times I \]Ohm's Law states the relationship between voltage, current, and resistance (\(R\)).
\[ V = I \times R \]Rearrange Ohm's Law to solve for \(I\):
\[ I = \frac{V}{R} \]Substitute \(I = \frac{V}{R}\) into the power formula \(P = V \times I\):
\[ P = V \times \left(\frac{V}{R}\right) \]Multiply the terms to get the final formula:
\[ P = \frac{V^2}{R} \]B) P = V2 / R is the correct formula for calculating power in terms of resistance and voltage, derived by substituting Ohm's Law into the basic power formula.
The question asks for the definition of 'apparent power' in an AC circuit. To answer this, we need to understand the different types of power in AC circuits: apparent power, real power (or active power), and reactive power. Apparent power is a fundamental concept representing the total power delivered to a circuit, without considering the phase difference between voltage and current.
Correct Option: B) The product of RMS voltage and RMS current
This question asks about the fundamental difference between real power and apparent power in AC circuits. Understanding these concepts is crucial for analyzing and designing AC power systems. We need to identify the definition that accurately describes real power and differentiates it from apparent power.
C) Real power is the actual power consumed, calculated as \( P = V_{\text{rms}}
The power factor in an electrical circuit is a crucial concept in AC power systems. It describes the efficiency with which electrical power is converted into useful work. It is defined as the ratio of the real power (actual power consumed by the load) to the apparent power (total power supplied to the circuit).
B) The ratio of real power to apparent power. This is the precise definition of the power factor in an electrical circuit, indicating the efficiency of power utilization.