Heat

Question 1

What are the different ways heat can be produced?

Answer 1

Heat can be produced by mechanical

Question 2

What is the relationship between heat energy and the internal energy of a body?

Answer 2

The relationship between heat energy and the internal energy of a body is that the total internal energy equals the sum of kinetic energy and potential energy due to molecular motion and attraction.

Question 3

How can you feel the difference between a hot and cold object?

Answer 3

You can feel the difference between a hot and cold object based on the direction of heat flow.

Question 4

What is the unit of heat in SI and CGS systems?

Answer 4

The unit of heat in SI system is joule (J) and in CGS system it is erg.

Question 5

How are calories and joules related?

Answer 5

Calories and joules are related such that 1 calorie is equal to 4.186 joules.

Question 6

What is the definition of temperature?

Answer 6

Temperature is defined as the degree of hotness or coldness of a body which determines the direction of heat flow when two bodies are placed in contact.

Question 7

What factors affect the heat energy contained in a body?

Answer 7

The factors that affect the heat energy contained in a body are mass

Question 8

What is the unit of temperature in kelvin?

Answer 8

The unit of temperature in kelvin is Kelvin (K).

Question 9

How are Celsius and Kelvin temperatures related?

Answer 9

Celsius and Kelvin temperatures are related by the equation K = 273.15 + °C.

Question 10

How are Celsius and Fahrenheit temperatures related?

Answer 10

Celsius and Fahrenheit temperatures are related by the equation C/5 = (F-32)/9.

Question 11

What is thermal expansion?

Answer 11

Thermal expansion is the expansion of a substance due to heating.

Question 12

What is the unique property of water related to thermal expansion?

Answer 12

The unique property of water related to thermal expansion is anomalous expansion where water expands when cooled from 4°C to 0°C.

Question 13

What instrument demonstrates the anomalous expansion of water?

Answer 13

Hope’s apparatus demonstrates the anomalous expansion of water.

Question 14

Describe the design of Hope’s apparatus.

Answer 14

Hope’s apparatus consists of a cylindrical vessel surrounded by an annular trough filled with a freezing mixture of ice and salt with thermometers placed at the top and bottom of the vessel to measure temperature variations.

Question 15

What is the initial temperature reading in both thermometers?

Answer 15

The initial temperature reading in both thermometers is the same.

Question 16

What happens to the lower thermometer reading as the central water cools?

Answer 16

The lower thermometer reading decreases to 4°C and stays steady.

Question 17

What happens to the upper thermometer reading during this time?

Answer 17

The upper thermometer reading remains almost unchanged during this time.

Question 18

What happens to the upper thermometer reading after the lower one reaches 4°C?

Answer 18

The upper thermometer reading decreases to 0°C indicating freezing.

Question 19

Explain the reason for the different temperature readings observed in the experiment.

Answer 19

The different temperature readings observed in the experiment are due to density changes of water caused by anomalous expansion.

Question 20

Calculate how many ergs are equal to 10 joules.

Answer 20

10 joules = 10 * 10^7 ergs = 10^8 ergs.

Question 21

Convert a temperature of 20°C to kelvin.

Answer 21

20°C + 273.15 = 293.15 K.

Question 22

If the mass of a body increases will its heat energy also increase? Explain.

Answer 22

Yes if the mass of a body increases its heat energy will also increase because heat energy depends on mass.