Physics
posted by Billy .
A circuit contains six 270 lamps and a 18.0 heater connected in parallel. The voltage across the circuit is 120 V.
(a) What is the current in the circuit when four lamps are turned on?
(b) What is the current in the circuit when all lamps are on?
(c) What is the current in the circuit when six lamps and the heater are operating?

R(Lp) = 270 Ohms each?
R(Htr) = 18 Ohms?
a. I = 4 * (120/270) = 1.78A.
b. I = 6 * (120/270) = 2.67A.
c. I = 2.67 + (120/18) = 9.34A
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