Temperature And Heat

The flow of heat is always from a body at higher temperature to a body at lower temperature, not the other way around. This is a fundamental principle of thermodynamics.

Statement (D) contradicts this law by stating that heat flows from low temperature to high temperature, which is incorrect.
All other statements correctly describe properties or effects related to temperature:

- It determines the direction of heat flow
- It helps define thermal equilibrium
- It indicates the degree of hotness or coldness of a body

Therefore, option (D) is the false statement.

The correct option is (D): Heat flows from a body at low temperature to a body at high temperature

The Kelvin and Celsius temperature scales are related by the formula: Given: So, is equal to 0 K, which is also called absolute zero, the lowest possible temperature.

The correct option is (C):

Correct answer:

Explanation:
Let:
- = temperature of hot water
- = temperature of cold water
- = final temperature after mixing
When hot and cold water are mixed, the final temperature will be between the temperatures of hot and cold water. That is: This is due to the principle of thermal equilibrium: heat flows from hot water to cold water until both reach a common intermediate temperature.

Hence, the correct answer is: .

Correct answer: B

Explanation:
To compare the temperatures of the two bodies, we need to convert the temperatures into the same scale. Let's convert both temperatures to Kelvin (K). - Temperature of A: -100°C
- Temperature of B: 173 K (already in Kelvin) Now, comparing the temperatures:
- Body A is at 173.15 K. - Body B is at 173 K.

Therefore, Body A is slightly warmer than Body B. Hence, Body A has a higher temperature. The correct answer is Body A is at a higher temperature.

Correct answer: calorie

The amount of heat required to raise the temperature of 1 gram of water by 1 °C is called a calorie. It is a unit of heat energy.

- 1 calorie = 4.184 joules. - Joule is a unit of energy, not specifically the amount of heat required to raise the temperature of water by 1°C.
- Kelvin is a unit of temperature.
- Degree Celsius is a unit of temperature change, not heat.

The Earth's oceans play a significant role in absorbing, storing, and redistributing heat. Oceans act as heat storage reservoirs due to their high specific heat capacity, meaning they can absorb and release large amounts of heat without significant temperature change. This helps in regulating the Earth's temperature.

The correct option is (D): Oceans

The principle of the method of mixtures is a concept in thermodynamics that deals with the thermal equilibrium achieved when a hot object is mixed with a cold object. This principle is based on the law of conservation of energy, which states that energy cannot be created or destroyed, only transferred. When two objects are mixed, the net heat lost by the hot object is equal to the net heat gained by the cold object until thermal equilibrium is reached.

In this context, if we denote:

• as the net heat lost by the hot object
• as the net heat gained by the cold object

According to the principle of conservation of energy, the heat lost by the hot object must equal the heat gained by the cold object, provided no heat is lost to the surroundings. Therefore, mathematically, this is expressed as:

This equation shows that the total heat lost by the hot substance is transferred entirely to the cold substance.

Thus, the correct answer is .

The Kelvin scale is an absolute temperature scale used in physics and chemistry.
To convert a temperature from Celsius to Kelvin, the following equation is used: K = °C + 273.15.

For this problem, we need to convert –10 ºC to Kelvin.
Applying the conversion formula gives:

K = –10 + 273.15 = 263.15 K

Since temperature values in Kelvin are typically expressed as whole numbers when dealing with typical temperature ranges, we can round 263.15 K to 263 K.

Therefore, the value of –10 ºC in Kelvin is 263 K.

We are given that .

We know that . So, .

Then we have

.

Then .

So, .

Therefore, .