# Number of Resistors needed for a maximum power

#### chawki

1. Homework Statement
How many resistors, R = 70 ohms can be connected in a series circuit when the maximum power loss of the circuit is 1800W. and the voltages supply is 127V

2. Homework Equations
Number of resistors!

3. The Attempt at a Solution
P = V2 / x*R
x*7=1272/1800
x=1.28

so only one resistor can be connected.

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#### gneill

Mentor
1. Homework Statement
How many resistors, R = 70 ohms can be connected in a series circuit when the maximum power loss of the circuit is 1800W. and the voltages supply is 127V

2. Homework Equations
Number of resistors!

3. The Attempt at a Solution
P = V2 / x*R
x*7=1272/1800
x=1.28

so only one resistor can be connected.
Are the resistors 7 Ω or 70 Ω? Your problem statement says 70, but you've used 7 in your calculation.

#### chawki

no it's 7 Ohms. sorry for the typing mistake.

#### SammyS

Staff Emeritus
Homework Helper
Gold Member
1. Homework Statement
How many resistors, R = 70 ohms can be connected in a series circuit when the maximum power loss of the circuit is 1800W. and the voltages supply is 127V

2. Homework Equations
Number of resistors!

3. The Attempt at a Solution
P = V2 / x*R
x*7=1272/1800
x=1.28

so only one resistor can be connected.
If R=7Ω , then this is correct !

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