An ideal 30V battery powers the circuit shown. Resistor R1=8Ω is connected in series with a branch containing two parallel paths:
• Path A contains only resistor R2=12Ω.
• Path B contains resistor R3=6Ω followed by a switch S in series with resistor R4=4Ω.
The switch can be either OPEN (no current through R4) or CLOSED (allowing current through R4). Wires are ideal.
(a) With the switch OPEN, determine the equivalent resistance of the entire circuit and the current delivered by the battery.
(b) With the switch OPEN, calculate the current through resistor R2.
(c) With the switch CLOSED, determine the new equivalent resistance of the circuit and the new current delivered by the battery.
(d) With the switch CLOSED, calculate the current through resistor R2.
(e) Compute the ratio of the power dissipated in resistor R1 when the switch is CLOSED to the power dissipated in R1 when the switch is OPEN. Explain qualitatively why this ratio is greater than, equal to, or less than one.