# Please tell me what the phase shift is?

Hi, what is the phase shift and how can you tell by looking at this graph ? From my understanding, a standard sine graph starts at (0,0) but where does this graph start ? How can I calculate the phase shift on this graph if I can't determine a starting point? Thanks.

### 2 Answers

- PhilomelLv 71 month ago
In an AC system, when the load is resistive the voltage and current graphs lie on top of each other, zero phase shift.

If the load is not resistive but is capacitive the current wave will lead the voltage wave by 90 degrees.

If the load is inductive, as in a motor, the voltage wave will lead the current by 90 degrees.

The Pneumonics are:

ELI the ICE man.

ELI; Voltage(E) leads the Current(I) in a capacitive(C) circuit.

ICE; Current(I) leads the voltage(E) in an Inductive(L) circuit.

Read Phase shift articles in Wikipedia.

Google : Phase shift wiki

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- RealProLv 71 month ago
The phase is related only to sine. How much the graph is shifted up/down really doesn't matter.

Since the midline is at y=3 we copy the x-axis there. The sine starts at approximately (-180°, 0)

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