temperature

Question 1

definition of temperature

Answer 1

temperature is a measure of how hot or cold an object is.

Question 2

si unit of temperature

Answer 2

kelvin(K).

Question 3

definition of heat

Answer 3

heat refers to the amount of thermal energy that is being transferred from a hotter region to a colder region.

Question 4

SI unit of heat

Answer 4

Joule(J)

Question 5

when is there net heat flow

Answer 5

when two identical objects at different temperatures are in contact with each other.

Question 6

what are thermometric substances

Answer 6

they are substances used in thermometers to measure temperature.

Question 7

properties of thermometric substances

Answer 7

thermometric substances have physical properties that vary uniformly and continuously with temperature.

Question 8

thermometric properties of mercury-in-glass/alcohol-in-glass thermometers

Answer 8

shows volume of a fixed mass of liquid.

Question 9

thermometric properties of resistance thermometers

Answer 9

electrical resistance of a piece of metal.

Question 10

thermometric properties of thermocouple thermometers

Answer 10

electrical voltage or electromotive force

Question 11

how to calibrate a thermometer

Answer 11

1. choose an appropriate thermometric substance.
2. choose 2 fixed points such as the ice and steam points.
3. then, divide the interval between the ice point into 100 equal parts. each interval representing 1 degree Celsius.

Question 12

definition of ice point

Answer 12

ice point is the lower fixed point and the temperature at which pure ice melts at one atmospheric pressure and is assigned the value of 0 C.

Question 13

definition of steam point

Answer 13

steam point is the upper fixed point and the temperature at which pure water changes to steam at one atmospheric pressure and is assigned the value of 100 C

Question 14

how can one determine the ice point

Answer 14

1. immerse the bulb and the lower part of the thermometer stem into a funnel containing melting ice.
2. when the mercury level is stable, make a mark l1 at that level on the stem. this is the ice point.

Question 15

how can one determine the steam point

Answer 15

1. insert the thermometer into the apparatus. the bulb should be just above the boiling water.
2. the stem of the thermometer should protrude from the top of the apparatus.
3. when the mercury level in the thermometer stem remains steady, make a mark l2 at that level on the stem. this is the steam point.

Question 16

what is a resistance thermometer

Answer 16

a resistance thermometer is a thermometer which consists of a platinum wire coiled around a piece of mica in a silica tube.

Question 17

what is a thermocouple

Answer 17

a thermocouple is a thermometer consisting of 2 wires made of different metals. the wires are joined to form 2 junctions, which produce a small emf when there is a temperature difference.