1. A coil of 1.25H inductance and a resistance of 600 ohms is placed in series with a 4.4Kohms resistor. This circuit is now connected to a power supply of 250v at 200Hz. What is the current flowing in the circuit?

so, I know that for RL circuit the equation is I=V/Z where Z=sq root(R^2 + w^2 L^2), but that does not include coil resistance (600 ohm here). How do I solve that?

2. A circuit consists of a 300 ohm resistor in series with a 3H coil and a 5uF capacitor. Determine the tangent of the angle of phase difference between the current and the applied e.m.f when the frequency is: a) 50Hz, b) 25Hz.

as far as I understand it is : tan()= (Xl-Xc)/R. is that correct?

3. Calculate the resonant frequency of a circuit consisting of a 400 ohm resistor in series with a 0 8.H coil and a 3uF capacitor.

now, I know how it goes for LC but not for RLC.

4. A circuit consists of a 0.16uF capacitor connected across a 20v, 1kHz supply. Also in parallel with the capacitor there is a 1K ohm resistor in series with a 0.16H coil. Calculate:

a) the current drawn from the supply; b) the phase angle of this current.

It doesn't sound that bad but i need to use j-operator in this one. And was never any good with complex notations.

Any help appreciated. Thx.