An extension cord made of two wires of diameter 0.129 cm(no. 16 copper wire) and

Question

An extension cord made of two wires of diameter 0.129 cm(no. 16 copper wire) and of length 2.9 m is connected to an electric heater which draws 16.5 A on a 120-V line. The resistivity of copper is 1.68×108m.

Part A

How much power is dissipated in the cord?

Express your answer to two significant figures and include the appropriate units.

SubmitMy AnswersGive Up

An extension cord made of two wires of diameter 0.129 cm(no. 16 copper wire) and of length 2.9 m is connected to an electric heater which draws 16.5 A on a 120-V line. The resistivity of copper is 1.68×108m.

Part A

How much power is dissipated in the cord?

Express your answer to two significant figures and include the appropriate units.

SubmitMy AnswersGive Up

Explanation / Answer

Resistance = resistivity x Length / crosssection area

R = (1.68 x 10^-8 x 2.9 ) / pi(0.129/2 x 10^-2 )^2

R = 0.0373 ohm

there are two wires so Req = 2R = 0.0745

Power = i^2R = 16.5^2 x 0.0745 = 20.30 W

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.