How do I find the resistance across a series circuit?

Question

The current through two identical light bulbs connected in a series circuit is 0.25 Amps. The voltage across both bulbs is 100V. What is the resistance of a single light bulb.

Answer 1

Are you series?
I meant serious?

Vt=V1+V2
R1=R2
Then V1=V2
R1=V1/I
V1=0.5Vt
R1=0.5Vt/I
R1=0.5 100/0.25
R1=R2=200 ohms

Oh, you've asked: "How do I find the resistance across a series circuit?"

Rt=Vt/I = 100/0.25= 400 ohms
Rt=R1+R2= ....

Answer 2

When trying to find the total resistance of a series circuit the formula is as follows Rtotal = R1 + R2 + R3 + R4...

To find the resistance of a circuit when you know the voltage and the current you would use the equation V=IR (Voltage = Current x Resistance).

In this case you're wanting to find the total resistance so it changes slightly to R=V/I.

R total = 100V / .25A

R total = 400 ohms

Now if the lightbulbs are identical the resistance of one should be half of the total resistance in the circuit.

R bulb = R total / 2

R bulb = 400 ohms / 2

R bulb = 200 ohms. Final answer.

Answer 3

R=V/I
V=100v
I=0.25A
R=100*100/25
=100*4
R=400 Ohm

Answer 4

E = I x R so R = E/I = 400 (for both bulbs together) so each bulb is 200 ohms