An old lamp contains a three-way liehthulb that can act as a 20 w, 55 w or 75 w light source when connected to 120 v. such a bulb contains just two resistive filaments (r4,rg). the switch on the lamp changes the circuit so the resistive filaments are connected to the 120v either individually or in parallel a) sketch the circuit(s) required to create this lightbulb-switch circuit, and describe how the connections to the two filaments are made to give each of the three wattages b) what is the resistance of each filament? /2 points 13. current from a battery with an unknown voltage passes through a resistor with an unknown resistance r. resulting in a current of 0.55 a. next, a second resistor with a resistance of r2= 18 is placed in series with r1 and the battery, resulting in a 0.25 a current. sketch the circuits and calculate r