In the article “Measurements of the Thermal Conductivity and Thermal Diffusivity of Polymer Melts with the Short-Hot-Wire Method”, the thermal diffusivity of a liquid measured by the transient short-hot-wire method is given by





where? is the thermal diffusivity; V and I are the voltage and current applied to the hot wire, respectively; l is the length of the wire; and A and a are quantities involving temperature whose values are estimated separately. In this article, the relative uncertainties of these quantities are given as follows: V, 0.01%; I, 0.01%; l, 1%; A, 0.1%; a, 1%.



a. Find the relative uncertainty in ?.

b. Which would reduce the relative uncertainty more: reducing the relative uncertainty in l to 0.5% or reducing the relative uncertainties in V, I, and A each to 0?


Trades & Technology

You might also like to view...

? Identify and state the historical significance ofDeWitt Clinton.

What will be an ideal response?

Trades & Technology

Diodes cannot be connected to produce full-wave rectification.

Answer the following statement true (T) or false (F)

Trades & Technology

When the outdoor temperature falls below the balance point, an air-to-air heat pump _____

a. must be shut down b. can no longer extract heat from the outside air c. requires supplemental heat d. can produce more heat than the structure requires

Trades & Technology

Which of the following is not an employability skill?

A. communication B. attitude C. tolerancing D. workplace safety

Trades & Technology