Why current leads the voltage in a capacitor ? |Does current lead or lag voltage in a capacitor?
The current in the pure capacitor leads the voltage by 90 degrees.
You know the capacitor is nothing but two conductors separated by a dielectric medium. When a capacitor is connected across a voltage source, the voltage doesn’t build up instantaneously. The capacitor starts charging slowly by taking the current from the source. Therefore, In a pure capacitive circuit the voltage cannot increase simultaneously with the current as the capacitor needs time to charge. This makes the voltage to follow the current and the voltage reaches its peak value some time after the current. Therefore, in a pure capacitive circuit, the current always leads the voltage by 90 degrees.

If you would like to watch more such videos, please subscribe to Build From Basics YouTube Channel.
Why Reactive Power is Necessary ? | The Best Explanation | What is Reactive Power ?
   • Why Reactive Power is Necessary ? | T...  

Why Transformers and AC Generators are rated in kVA instead of kW ?
   • Why Transformers and AC Generators ar...  

Why does current lags behind voltage in an Inductor ?
   • Why does current lags behind voltage ...