What is the power factor for a purely inductive or purely capacitive AC circuit?
0
In an AC circuit, power factor (PF) is defined as the cosine of the phase angle (ϕ) between the current and voltage. It is represented as:
PF = cos(ϕ)
1. In purely inductive or purely capacitive circuits, the phase difference between current and voltage is 90 degrees because:
- In a purely inductive circuit, voltage leads the current by 90°.
- In a purely capacitive circuit, current leads the voltage by 90°.
2. For a 90-degree phase difference, the cosine value is:
cos(90°) = 0
3. Therefore, the power factor for both purely inductive and purely capacitive circuits is:
0
Thus, the correct answer is 0.
Important Questions from Power in Electric Circuits
An electric bulb is connected to 220 V generator. The current drawn is 600 mA. What is the power of the bulb?
- What is the current required to light a 60 W incandescent bulb in a domestic supply of 240 V ?
An electric bulb is connected to a 200 V generator. The current drawn by the bulb is 0.1 A. What is the power of the bulb?
Convert $1 \text{ MWh}$ (megawatt-hour) into Joules.
- Two incandescent bulbs are rated at $P_1 = 200\,\text{W}$ and $P_2 = 100\,\text{W}$, respectively, when operated at a voltage of $V_{rated} = 220\,\text{V}$. If these two bulbs are connected in series across a $V_{supply} = 110\,\text{V}$ DC power supply, determine which bulb will glow brighter and by what factor compared to the other bulb.
