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A current i passes through a wire of length L, radius R and resistively rho. The rate of heat generated is

A. irhoL/πr²
B. i2(Lrho/πr²)
C. (i²rhoL/r)
D. noneofthese

User Uche
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1 Answer

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Final answer:

The correct formula for the rate of heat generated in the wire is B. i²(Lρ/πr²), where 'i' is the current, 'ρ' is the resistivity, 'L' is the length, and 'r' is the radius of the wire.

Step-by-step explanation:

The question is about calculating the rate at which heat is generated by a current flowing through a wire with given physical properties.

The rate of heat generated by the wire is a result of the electrical resistance, which can be expressed using the resistivity (ρ), length (L), and cross-sectional area (A = πr² where 'r' is the radius of the wire).

The formula for electrical power, which is the rate of heat generation, is P = I²R, where I is the current and R is the resistance of the wire. The resistance R of the wire, using resistivity, is given by R = ρL/A.

Substituting for R and A, you get P = I²(ρL/(πr²)). Thus, the correct formula for the rate of heat generated is B. i²(Lρ/πr²).

User Kporter
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