Tag: transfer of heat

Quizzes (8) Questions (172)

Questions Related to transfer of heat

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

Define insulator of heat.

  1. Substances through which heat can pass easily are called insulators of heat.

  2. Substances through which heat cannot pass easily are called insulators of heat.

  3. Substance which can easily freeze are called insulators of heat.

  4. Substances which cannot freeze easily are called insulators of heat.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Insulators are  through which heat cannot pass easily.

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

State whether given statement is True or False
Iron is a better conductor of heat than copper

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Thermal conductivity is quantity of heat transmitted due to temperature gradient in unit time under steady conditions in a direction normal to surface of unit area.
Thermal conductivity of copper = 386
Thermal conductivity of iron at $68^oC$ is 73

Thermal conductivity of copper is greater than iron.
Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

State True or False :
Good conductors of heat are also good conductors of electricity. 

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Usually, good conductors of heat are also good conductors of electricity. However, this is not always true. One of the exceptions is mica. Mica is good conductor of heat but bad conductor of electricity.

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

Conductors become hot easily because they have:

  1. high specific capacity

  2. low specific heat capacity

  3. high freezing point

  4. low freezing point
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Specific heat capacity is the amount of heat required to raise the temperature of a unit mass by one degree. Materials with low specific heat capacity require less energy to increase their temperature, thus they become hot easily.

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

In general, metals have very low :

  1. Boiling Point

  2. Freezing Point

  3. Melting Point

  4. Specific Heat Capacity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In conduction, heat is transferred by the vibrations of molecules. The density of conductors is large, it means molecules are close to each other, because of that they can easily transfer the heat quickly through the whole conductor, therefore unit mass of conductors require small heat to raise their temperature through $1^{o}$ i.e. conductors have very low specific heat. 

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

Specific heat capacity is ______ for conductors of heat and _______ for insulators of heat.

  1. low, low

  2. low, high

  3. high, high

  4. high, low
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$Q=ms\Delta T$,

where 
$Q: \text{the amount of heat delivered to a body}$
$m: \text{mass of the body}$
$s: \text{specific heat capacity of the body}$
$\Delta T: \text{Change in temperature of the body}$

If $Q\ \text{and}\ m$ are constant, 
$\Delta T \propto \dfrac{1}{s}$

So for small $s, \Delta T$ is more and hence it is better conductor of heat.