WTMA Heat Transfer and Conduction 5

Question 1

A worker holds a copper wire in a flame. Within seconds the far end becomes too hot to touch. This happens because copper:

Accepted Answer

Has very high thermal conductivity

Answer

Copper is one of the best thermal conductors among common metals, so heat travels quickly along its length.

Question 2

An oven mitt with thick padding protects a cook's hand by:

Accepted Answer

Providing a thick layer of low-conductivity material that slows heat transfer

Answer

The thick, low-conductivity padding creates high thermal resistance, slowing heat flow to the hand.

Question 3

Two identical metal blocks—one at 200°F, one at 70°F—are placed in contact. Heat will flow:

Accepted Answer

From the hotter block to the cooler block

Answer

Heat always flows spontaneously from higher temperature to lower temperature until equilibrium is reached.

Question 4

Which modification to a metal rod would MOST increase the amount of heat it can conduct per minute?

Accepted Answer

Increasing its cross-sectional area

Answer

Larger cross-sectional area provides more pathways for heat to flow, increasing total conduction rate.

Question 5

A steam pipe is insulated with fiberglass wrap. Which statement is correct about the fiberglass?

Accepted Answer

It has low thermal conductivity, reducing heat loss to the surroundings

Answer

Fiberglass is an effective insulator because its low thermal conductivity greatly resists heat conduction outward.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test