Give three elements X, Y and Z to be connected across an ac source . With only X connected across the ac source voltage and current are found to be in the same phase . With only element Y in the circuit the voltage lage behind the current in phase by `pi//2` while with the element Z in the circuit the voltage leads the current in phase by `pi//2` .
(a) Identify the elements X, Y and Z .
(b) When all these elements are connected in series across the same source (i) determine the power factor and (ii) find out the condition when the circuit is in resonant state .

Explanation

To solve the given problem step by step, we will address both parts (a) and (b) of the question.

### Part (a): Identify the elements X, Y, and Z.

1. **Element X**:
- The problem states that when only element X is connected to the AC source, the voltage and current are in the same phase. This condition is characteristic of a **resistor**.
- Therefore, **X = Resistor**.

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