Impedance and resistance are two important concepts in the field of electrical engineering. Resistance is a measure of the opposition to the flow of electrical current through a conductor, whereas impedance is a measure of the total opposition to the flow of electrical current through a circuit.


The relationship between impedance and resistance is given by the following equation:
Impedance (Z) = √3 x Resistance (R)


Phase difference is the difference in phase angle between two alternating quantities of the same frequency. In an AC circuit, the current and voltage are out of phase by some angle.

The phase difference between the current and voltage in an AC circuit can be calculated using the following formula:
Phase difference (θ) = cos⁻¹(Power factor)

The power factor is defined as the ratio of the real power (P) to the apparent power (S) in an AC circuit.

The power factor can be calculated using the following formula:
Power factor = P/S

where P = VIcosθ is the real power, V is the voltage, I is the current, and θ is the phase difference.


In conclusion, when the impedance is root 3 times of resistance, the phase difference between the current and voltage in an AC circuit can be calculated using the above formulae. The phase difference depends on the power factor, which is the ratio of real power to apparent power in the circuit.