Inductance 5.1 1. Find the inductance of the air-core coil with the following dimensions. length = 100mm, diameter = 4mm, # of turns = 50 2. A 100 turn air cored coil is placed in a magnetic field that is varying at 2 Webers/second. What is the expected voltage across the coil? 3. If the length of the coil from above is 20 mm and the cross sectional area is 100 mm2 what is the inductance of the coil? 4. We apply a signal with the current shown below to the coil. Sketch the expected voltage across the coil. 10 8 6 4 2 0 0 2 4 6 8 10 millisec 5. The circuit below is alternately connected to the battery for 2.5 ms then disconnected for 2.5 ms. Sketch the expected voltage across the inductor for these periods. 1kΩ 1k Ω iL 0.5H 10 V 6. What is the impedance looking into the circuit below at the frequency shown? 1 volt Z 100 Ω 1.5 μF 20mH 100 Hz 7. You have an RL series circuit with a resistor value of 10K ohms and an inductor of 0.2mH. If the phase angle of the total impedance equals 30 degrees, what frequency must the input signal be. 8. The reactance of an inductor is 1200 ohms for f = 280Hz. What is its inductance? 9. A resistor, an inductor, and a capacitor are connected in series across a voltage source. A digital voltmeter measures their AC voltage at 12.0V, 15.5V and 10.5V, respectively, when place across each element. What is the voltage of the source? Assume the components are ideal. 10. Given an RCL series circuit and that R = 12.0 Ω, L = 0.300 H, C = 250μF, ω =80.0 rad /sec, determine the impedance and the phase difference between the current and the voltage supply. Q. 11 A 60V ac voltage source is connected to a series circuit consisting of a resistor, a capacitor and an inductor. The voltage across the inductor is 60V, and the voltage across the capacitor is 60V. What is the voltage across the resistor?