Question

Assume batteries and generators provide the stated potential difference for any current that flows. A 10-Ω resistor, a 15-Ω resistor, and a 5-Ω resistor are connected in a series across a 90-V battery.
a. What is the equivalent resistance of the circuit?
b. What is the current in the circuit?

Answer 1

So it's
|---( 10-Ω )----|
| ( 15-Ω )
(90V) |
| |
|-----( 5-Ω )---|

The resistance in the circuit would just be 10-Ω + 15-Ω + 5-Ω = 30-Ω
Because their in series.

For the other question: How to calculate voltage drop across series resistors.

Determine current of total resistors across the series.

(I = Current/V=Voltage/R(t)=Resistance Total)
I = V / R(t)
I = 90V / (30-Ω)
I = 3 A

Now that we have the Current across the resistors we can calculate the voltage across EACH resistor.

I = Current
Vx = Voltage (x = Current Value across X Resistor)
Rx = Resistor value(x = resistor#)

V = I x Rx

V1 = 3 A x 10
V1 = 30V

V2 = 3 A x 15
V2 = 45V

V3 = 3 A x 5
V3 = 15V

V1 + V2 + V3 = 30V + 45V + 15V = 90V =Vtotal