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In the ac waveform of a capacitor the current waveform leads the voltage waveform

current is large to start until capacitor fills with it's voltage charge if that helps

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The terms 'leading' and 'lagging', used when describing power factor, are defined in terms of whether the load current is leading or lagging the supply voltage.

In a capacitive circuit, the load current leads the supply voltage, so the power factor is leading.

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13y ago

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A capacitor has to have current through it before it develops a voltage across it. The voltage (in volts) across a capacitor is the capacitance (Farads) times the current (Amps) times the time (seconds).

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9y ago
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Because current must flow in a capacitor before any voltage appears across it.

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11y ago
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because, capacitor reactance is small.

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12y ago
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Q: Why current leading in capactor?
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How does a ujt relaxation oscillator work?

The operation of the circuit is as follows: C1 charges through R1 until the voltage across it reaches the peak point. The emitter current then rises rapidly, discharging C1 through the base 1 region and R3. The sudden rise of current through R3 produces the voltage pulse. When the current falls to IV the UJT switches off and the cycle is repeated.


What lagging or leading?

You must knew there's a sinusoidal wave form for both voltage nd current. That wave form is drawn between voltage/current nd phase angle. Unity: phase angle of voltage nd current matches, irrespective of magnitude leading: phase angle of current leads voltage by an angle lagging: phase angle of voltage leads current or current lags voltage by an angleAnswerThe terms, 'leading' and 'lagging' apply to a.c. loads. 'Leading' means that the load current leads the supply voltage, whereas 'lagging' means that the load current lags the supply voltage. 'Leading' currents occur in capacitive loads, whereas 'lagging' currents occur in inductive loads.'Leading' and 'lagging' refers to what the current is doing, relative to the voltage, never the other way around.


What is meant by leading and lagging pf?

Power Factor is the ratio of true vs apparent power, and comes into play with a reactive (inductive or capacitive) load. A purely resistive load, such as a light bulb or toaster, will have a power factor of 1 because the current is in phase with the voltage. An inductive load, however, such as a motor, will have a power factor less than 1 because the current lags the voltage. You could also have a capacitive load, with a power factor less than 1, but in this case the current leads the voltage.AnswerThe terms, 'leading' and 'lagging' refer to whether a circuit's load current is leading or lagging the supply voltage. Current will 'lead' in resistive-capacitive (R-C) circuits, and 'lag' in resistive-inductive (R-L) circuits. So, a 'leading power factor' indicates a leading current, and applies to R-C circuits, while a 'lagging power factor' indicates a lagging current, and applies to R-L circuits.


If capacitors dont use ac current then how and why are they used in most appliances?

Capacitors resist a change in voltage, proportional to capacitance and current. This is called capacitive reactance. As a result, a capacitor in an AC circuit will create a leading phase angle, current relative to voltage. This, for example, can be used to help start a motor by creating two magnetic fields, one leading the other.


Why voltage across capacitor goes to zero when wires connected to each terminal of charged capacitor are brought into contact?

The voltage goes to zero because a current path has been created between the positive and negative elements of the capacitor, discharging the stored charge and putting both the anode and cathode of the capactor at the same electrical potential. Thus, no voltage difference between them, which is why the voltmeter reads zero.