Question

Blender Impedance A blender that is actively blending is modelled as a resistor in series with an inductor. Its motor windings and electromechanical parts combined form an inductor of 35 millihenries and the a resistance of 7.2 ohms. It is connected to a standard United Kingdom household socket, with voltage 240V RMS and frequency 50Hz. a) What is the device's impedance (at 50Hz)? b) What is the RMS phasor current draw (in polar form, angle in degrees)

Answer 1

Resistance, R = 7.2 ohms

Inductance, L = 35 mH

supply frequency, f = 50 Hz

(a) Device impedance, Z = ( R + j X_L ) = ( R + j 2*pi*f*L) = ( 7.2 + j 2*pi* 50* 35*10^-3) ohms = (7.20 + j 10.96) ohms

(b) RMS current , I = V / Z = ( 240 / (7.20 + j 10.96)) = (ans)

18.3022 – 56.700 A (rms)