Answer: Option D. -> Reflection
:
D

There are three modes of heat transfer: conduction, convection and radiation. Any energy exchange between bodies occurs through one of these modes or a combination of them. Conduction is the transfer of heat by physical contact. Convection uses the movement of fluids to transfer heat. Heat radiation is the transfer of heat energy through electromagnetic waves. Radiation doesn't require any medium.
Reflection means bouncing of light wave when it strikes an object. It is not a mode of heat transfer.

Answer: Option C. -> Radiation
:
C
Out of all the modes of heat transfer, radiation is the fastest. This is because, it does not require any medium and it travels in the form of waves.

Answer: Option B. -> Kink
:
B

A kink prevents the mercury from falling down easily. A kink in the glass tube resists the flow of the mercury as it contracts, storing the highest temperature reading. Shaking the thermometer resets the mercury back into the bulb.

Answer: Option B. -> Kink
:

Types: 1 Mark
Use: 1 Mark
The various types of thermometer are:

i) Clinical Thermometer
ii) Laboratory Thermometer
iii) The maximum-minimum thermometer
The maximum and minimum temperature is used to record the extremes of temperature at a location.  

Answer: Option B. -> Kink
:
Definition: 0.5 Marks
Example: 0.5 Marks
Temperature is the degree of the hotness or coldness of a body.
Degree Celcius ( ${}^{\circ }C$), degree Fahrenheit ( ${}^{\circ }F$) and Kelvin(K) are the units of temperature.

Answer: Option B. -> Kink
:

Definition: 1 Mark
Range: 1 Mark
A clinical thermometer is a temperature measuring device used to measure only the body temperature.
The range of a clinical thermometer is 35${}^{\circ }$C to 42${}^{\circ }$C.

Answer: Option B. -> Kink
:
Clinical Thermometer: 1.5 Marks
Laboratory Thermometer: 1.5 Marks
The clinical thermometer is used to measure the temperature of human body. Hence, its use is limited for temperatures around 37 degrees Celcius. These thermometers thus have a range of 35${}^{\circ }$ C to 42${}^{\circ }$ C. It gives a more accurate measurement. It also has a kink, which holds the reading of mercury even when its taken away from contact.
Laboratory thermometers can be used to measure a variety of substances. These substances can be very hot or even very cold. For such reasons, it has a relatively broader area of measurement. These thermometers also do not have any kink, hence, the temperature is measured while the thermometer is still in contact.
Th range of laboratory thermometers is -10${}^{\circ }$ C to 110${}^{\circ }$ C.

Answer: Option B. -> Kink
:

Reasons:1 Mark each
Woollen clothes: 1 Mark
Dark coloured clothes absorb more heat so we feel comfortable in dark coloured clothes in winter.
We wear light coloured clothes in summer because they reflect most of the heat that falls on them.
Woollen clothes keep us warm during winters because they are poor conductors of heat. They trap our body heat, thus keeping us warm.
 

Answer: Option B. -> Kink
:
Range: 1 Mark
Precautions: 2 Marks
The range of a laboratory thermometer is -10˚C to 110˚C.
We need to take the following precautions while taking the readings from a laboratory thermometer:
i) It should be kept upright and not tilted while taking the observation.
ii) The bulb should be surrounded on all the sides by the substance of which the temperature is to be measured.
iii) The bulb should not touch the container.

Answer: Option B. -> Kink
:

Difference: 2 Marks
Cooking: 1 Mark
Conduction: Conduction is the process of transfer of heat from the hotter part to the colder part of an object without the movement of the particles. Also, in conduction, heat gets transferred between substances that are in direct contact with each other.

Convection: It is the process of transfer of heat by the movement of particles of a medium from one place to another. It takes place in liquid and gases.
Cooking of food usually uses a combination of conduction, convection and radiation. Conduction transfers the heat using direct contact; food is heated directly in a metal pan, in a liquid, or surrounded by air. Dropping an egg into a pan of boiling water is a good example. Convection occurs by the movement of air, liquid, or steam around the food. For example, as a pan of soup heats up on the stove, heat moves from the bottom of the pan. Heat transfer by radiation occurs when microwave (light waves) or infrared energy (heat waves) is spread into the food. As the microwaves penetrate the food, they bump into molecules of water and fat, causing them to vibrate rapidly. This vibration creates friction, which creates heat that cooks the food.