# Combination circuit with Series & Parallel light bulbs

• Engineering
dss975599

## Homework Statement

One 18 watt lamp and two 60-watt light bulb are plugged into a 120V circuit. For either DC or AC, the two bulbs are connected each other in parallel and in series with the lamp in the same circuit. Calculate;
i. the current flow through each light
ii. the total resistance of the circuit,

The soultion provided is I1 = P /V = 18 /120 = 0.15A ,
I2 = P / V = 60/120 = 0.5A

## The Attempt at a Solution

I have tried to sketch the diagram as attached .

R1= 120/ 0.15 = 800 ohm , R2 = 120/0.5 = 240 ohm
I doubt the ans is correct . When i check thru the working again , i found that the V total = 0.15(800) + 0.5(240) = 240V ....

So , i think it's wrong ...

Correct me if i am wrong

#### Attachments

• 946.png
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Your sketch is wrong. See this one: #### Attachments

• dss975599 and Tom.G
dss975599
Your sketch is wrong. See this one:
View attachment 227053
R1= 120/ 0.15 = 800 ohm , R2 = 120/0.5 = 240 ohm
I doubt the ans is correct . When i check thru the working again , i found that the V total = 0.15(800) + 0.5(240) = 240V ....

So , i think it's wrong ...

Correct me if i am wrong