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Why does current lag behind voltage in inductor?
Hence, when a sinusoidal voltage is applied to an inductor, the voltage leads the current by one-fourth of a cycle, or by a 90º phase angle. Current lags behind voltage, since inductors oppose change in current. Changing current induces an emf. This is considered an effective resistance of the inductor to AC.
In which circuit does the current lag the applied voltage by 90 degrees?
The only phase angles between the current and voltage which don’t dissipate any energy over a complete cycle are +90 and -90 degrees. The current lags the voltage by 90 degrees in an inductor, and leads it by 90 degrees in a capacitor.
How much does current lags voltage in inductor?
Current lags voltage by 90° in an inductor. Mathematically, we say that the phase angle of an inductor’s opposition to current is 90°, meaning that an inductor’s opposition to current is a positive imaginary quantity.
Why does the current lag the applied voltage in an inductor?
The current lags the voltage by 90 degrees in an inductor, and leads it by 90 degrees in a capacitor. For real inductors and capacitors, their internal resistance does dissipate some electrical energy as heat, and the phase angle is not exactly 90 degrees. The phase angle in a resistor is of course zero.
How is the energy stored in an inductor?
They store the energy in a magnetic field (inductor) or electric field (capacitor) as the applied current (inductor) or voltage (capacitor) increases, and release it again as it decreases. The only phase angles between the current and voltage which don’t dissipate any energy over a complete cycle are +90 and -90 degrees.
Why is the current always constant in an inductor?
In the inductance, being a coil, a magnetic field is generated by circulating a current through it. This current is maintained if the voltage to the coil is suddenly stopped. This generates that the current, in the inductance, is constant before sudden changes in the voltage.
Why does current lag when voltage is sinusoidal?
When you apply time-varying voltage, the current cannot immediately follow this variation, a consequence of which is the phase lag when the voltage is sinusoidal. The mathematical way of saying this is that up to a constant, the current is proportional to the time integral of the voltage.