A 9.3 ohm resistor and a 5.7 ohm resistor are connected in series with a power supply.

(a) The voltage drop across the 5.7 ohm resistor is measured to be 11 V. Find the voltage output of the power supply.
(b) The two resistors are connected in parallel across a power supply, and the current through the 9.3 ohm resistor is found to be 0.25 A. Find the voltage setting of the power supply.

I'll take this to the tutorial center tomorrow if I can't figure it out... but can someone help get me started please? Thanks

9/19/2006 8:29:58 PM

V = Power Supply Voltage
R1 = 9.3 ohm resistor
R2 = 5.7 ohm resistor
V1 = Voltage across R1
V2 = Voltage across R2

(a) The two resistors are in series, so the power supply voltage is dropped across the total resistance. Using Ohm's Law:

     V = I (R1 + R2)

     V2 = I * R2

9/19/2006 9:22:34 PM

sweeeet, thanks a lot!

9/19/2006 11:31:57 PM

Three 100 resistors are connected as shown in Figure P18.12. The maximum power that can safely be delivered to any one resistor is 28.5 W.

Two of the 100 resistors are parallel while the third one is alone

Figure P18.12
(a) What is the maximum voltage that can be applied to the terminals a and b?

9/25/2006 10:41:48 PM