physics
posted by Natasha on .
Two resistors, 68.0 Ω and 74.0 Ω, are connected in parallel. The current through the second resistor is 4.60 A.
(a) Determine the current in the first resistor?
(b) What is the total power supplied to the two resistors?

U=I1•R1=I2•R2,
I1=I2•R2/R1=
=4.6•74/68 = 5.01 A.
1/R=1/R1+1/R2,
R=R1•R2/(R1+R2) = 68•74/(68+74)=35.44 Ohm.
I=I1+I2=4.6+5.01=9.61 A.
P=I²•R=(9.61)² •35.44 = 3273 Watt.