A large AC electric motor under load can be considered as a parallel combination of resistance and inductance. If the equivalent resistance is 20 Ω and the inductance is 238 mH, calculate the rms current delivered by the 60 Hz, Vrms = 240 V AC power supply.
In an AC circuit, a filter circuit or filter removes unwanted frequency
components from an input. A passive filter consists of a circuit with at
least one reactive component. A filter with a single reactive component,
either a capacitor or an inductor, is called a first-order filter. Filters
are described according to their behavior. A low-pass filter will pass all
signals below a specific frequency, but will attenuate or block signals of a
higher frequency. A high-pass filter will do just the opposite. The
boundary line is somewhat arbitrary since there exists a "transition zone".
The cutoff frequency is defined as the frequency at which |Vout| = 2-½|Vin|.
Inspect the filter shown below. Identify what type of filter this circuit is, and calculate the size of resistor necessary to give it a cutoff frequency of 3 kHz: