Four resistors are connected to a battery with a terminal voltage of 12.0 V, (R1 = 40.0 , R2 = 80.0 , R3 = 140.0 and R4 = 15.0 )

(a) Determine the equivalent resistance for the circuit.
1
(b) Determine the current in the battery.
2 V
(c) Determine the current in the 40.0 resistor.
3 A
(d) Determine the power dissipated by the 80.0 resistor.
4 W
(e) Determine the power dissipated by the 15.0 resistor.
5 W
(Hint: Remember that P= (ÄV)2/R = IÄV.)
_ i don't understand how to do this at all??? HELP

1 answer

Assuming the load is not too great, and that the resistors are in parallel, then

1/R = 1/40 + 1/80 + 1`/140 + 1/15
R = 9

I = V/R = 12/9 = 1.3 A

I(40) = 12/40 = .3 A

P(80) = 144/80 = 1.8 W
P(15) = 144/15 = 9.6 W