Provide the solutions to these questions:
1. The potential difference measured across a coil is 4.5V when it carries a direct current of 9A. The same coil when carries an alternating current of 9A at 25Hz, the potential difference is 24V. Find the current, the power and the power factor when it is supplied by 50V, 50Hz supply.
2. In a particular R-L series circuit a voltage of 10V at 50Hz produces a current of 700mA while at the same voltage at 75Hz produces 500mA. What are the values of R and L in the circuit?