Heat

C

$^{\circ}\text{C}$

deg C

Celsius

Convection

Conduction

Radiation

None of these

Celsius scale

Fahrenheit scale

Kelvin scale

None of these

Mercury is a metal

It has a high boiling point

There is a constriction or kink in the tube

The glass is a bad conductor

$308 \text{ K}$

$35 \text{ K}$

$273 \text{ K}$

$238 \text{ K}$

Conduction

Convection

Radiation

Evaporation

To make it look modern

To reflect all the heat back

To absorb more heat from the sun

To prevent the cooker from rusting

Gases have low heat capacity and the thermometer absorbs all their heat.

Gases are poor conductors of heat.

Gases do not expand when heated.

The mass of gas is usually too small to affect the thermometer.

$45^{\circ}\text{C}$

$50^{\circ}\text{C}$

$55^{\circ}\text{C}$

$60^{\circ}\text{C}$

The total potential energy of its molecules.

The total internal energy of its molecules.

The average kinetic energy of its molecules.

The total heat energy contained in the body.

Increase in temperature

Change of state

Increase in mass

Chemical change

Joule

Watt

Calorie

Newton

Iron

Copper

Wood

Aluminum

Gain

Lose

Maintain

Double

Solid

Liquid

Gas

Plasma

All metals expand by the same amount.

Different metals expand by different amounts for the same temperature rise.

Metals contract on heating.

Heat cannot pass through metals.

Save concrete material.

Allow rainwater to seep through.

Provide space for the concrete to expand in summer.

Reduce the cost of construction.

Only the change in kinetic energy

Only the change in potential energy

The changes in both kinetic and potential energy

The change in nuclear energy

It is a liquid at room temperature

It has a uniform and high rate of expansion

It is opaque and shiny

It does not stick to the glass

Molecules stop moving

Molecules move slower and come closer

Molecules move faster and further apart

Molecules change into atoms

It requires a material medium to travel

It travels in straight lines

It is slower than convection

It only travels in the downward direction

Convection

Conduction

Radiation

Reflection

To prevent heat loss by conduction

To prevent heat loss by convection

To minimize heat loss by radiation

To make the flask stronger

Solids do not have heat

Molecules in solids are fixed and cannot move from place to place

Solids are too dense

Molecules in solids move too fast

They are good conductors of heat.

They are poor conductors of heat and protect the hand.

They help in radiating the heat faster.

They are cheaper than metals.

To increase their body weight.

To trap a layer of air which acts as an insulator.

To better reflect the sun's radiation.

To facilitate heat loss from their body.

The cup is a good conductor.

The thermos flask minimizes heat loss by conduction, convection, and radiation.

The cup allows more radiation to escape.

The flask generates its own heat.

Land heats up faster than water, causing air above land to rise and cool air from the sea to take its place.

Sea water is a better conductor of heat than the soil on land.

Radiation from the sun is stronger over the water than over the land.

The high density of sea water pushes the air towards the land.

Can A, because evaporation causes cooling, which is a form of heat transfer.

Can B, because air is a better conductor than water.

Can A, because water in the cloth is a better conductor than dry cloth.

Can B, because the dry cloth prevents convection better.

It travels in straight lines at the speed of light.

It can only travel through solids and liquids.

It is a slow process compared to conduction.

It requires a medium with high density to propagate.

The inner glass wall

The outer metal case

The stopper and the base support

The silver coating

One method only

Two methods only

Three methods (Conduction, Convection, Radiation)

No methods at all

Conduction

Convection

Radiation

Expansion

The vacuum remains

Air rushes in and the vacuum is lost

The vacuum turns into a solid

The vacuum becomes twice as strong

Conduction via glass, Convection via vacuum, Radiation via stopper

Conduction via vacuum, Convection via silvering, Radiation via stopper

Conduction via vacuum/stopper, Convection via vacuum, Radiation via silvering

Conduction via silvering, Convection via stopper, Radiation via vacuum

Cork

Hollow plastic

Solid Aluminium

Rubber

It is where the silvering was injected

It is the point where the air was sucked out and the flask was sealed

It acts as a shock absorber

It allows the flask to expand when heated

It provides the primary insulation by trapping a layer of air around the glass.

It protects the fragile vacuum-sealed glass vessel and provides a mounting for the handle.

It acts as a secondary vacuum chamber to double the insulation.

It is silvered on the inside to reflect heat back toward the glass.

To increase the volume of the liquid it can hold.

To better withstand the atmospheric pressure acting on the vacuum space.

To make the silvering process easier to perform.

To ensure that all the liquid can be poured out easily.

Heat would still be lost through conduction via the neck and the stopper.

Gravity would eventually pull the heat out through the bottom.

The atoms in the liquid would undergo radioactive decay.

Cosmic rays would penetrate the vacuum and provide heat.