Chapter 14 Thermodynamics, Heat Transfer, Thermal Conductivity and Thermometry

Question 1

What is the first law of thermodynamics

Answer 1

Energy is conserved; energy can neither be created nor destroyed; the sum of all energy remains the same

Can be transformed from one form to another without loss
heat and energy mutually convertible

Question 2

what is the second law of thermodynamics

Answer 2

energy always seeks a lower level

Thermodynamic processes are irreversible

Question 3

What is convection

Answer 3

heat transfer that involves movement of a fluid

heat traveling from tube to airstream

Question 4

What is conduction

Answer 4

heat transfer that involves movement of electrons within a material
(heat traveling through a rod)

Question 5

What is radiation

Answer 5

heat transfer that involves electromagnetic energy
heat source emits radiant energy
(the sun)

Question 6

define conductivity

Answer 6

The ability to conduct heat

Question 7

what’s the relation between thermal conductivity value and the ability to conduct heat

Answer 7

higher thermal conductivity means it’s easier to conduct heat

Question 8

what are two ways to measure temperature

Answer 8

Thermocouples and thermistors

Question 9

How do thermocouples measure heat

Answer 9

it is a bi-metal method that creates a small voltage. This voltage measured is proportional to temperature

Question 10

How to thermistors measure heat

Answer 10

Measures resistance to determine the temperature
As resistance decreases, temperature increases
A suitable substitute for thermocouples where low cost is important