A rod of 2.0-m length and a square (2.0 mm * 2.0 mm) cross section is made of a material with a resistivity of 6.0 * 10-8 Ω ⋅ m. If a potential difference of 0.50 V is placed across the ends of the rod, at what rate is heat generated in the rod?

Question

Freddy

Physics

1 July, 05:12

A rod of 2.0-m length and a square (2.0 mm * 2.0 mm) cross section is made of a material with a resistivity of 6.0 * 10-8 Ω ⋅ m. If a potential difference of 0.50 V is placed across the ends of the rod, at what rate is heat generated in the rod?

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Answers (1)

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Peters · Answer 1

8.33 x 10^-16 Watt

Explanation:

l = 2 m, A = 2 x 2 mm^2 = 4 x 10^-6 m^2

resistivity, p = 6 x 10^-8 ohm metre, V = 0.5 V

Let R be the resistance of teh rod

R = p x l / A

R = 6 x 10^-8 x 2 / (4 x 10^-6) = 3 x 10^14 ohm

Heat generated per second = V^2 / R = (0.5) ^2 / (3 x 10^14)

= 8.33 x 10^-16 Watt