The question asks for the SI unit of heat. We need to identify the standard international unit for energy, as heat is a form of energy transfer.
Correct Option: A) Joule is the SI unit of heat. Heat is a form of energy, and the SI unit for all forms of energy (including work) is the Joule (\(J\)). One Joule is defined as the work done when a force of one Newton moves an object by one meter. Mathematically, \(1 \text{ Joule} = 1 \text{ Newton} \times 1 \text{ meter}\) or \(1 \text{ J} = 1 \text{ N} \cdot \text{m}\).
The question asks to identify the fundamental nature of heat. We need to recall the basic definitions of physical quantities like matter, energy, force, and work.
Correct Option: B) Energy
Heat is a form of energy. Specifically, it is the transfer of thermal energy from one system to another due to a temperature difference. The SI unit of heat is the Joule (J), which is also the SI unit of energy.
The question asks to identify the device used for measuring heat. This requires knowledge of common scientific instruments and their functions.
Based on these definitions, the calorimeter is the correct device for measuring heat.
B) Calorimeter — A calorimeter is an instrument used to measure the heat of chemical reactions or physical changes as well as heat capacity. It quantifies the amount of heat absorbed or released in a process.
The question asks to identify the mode of heat transfer that occurs through direct contact. We need to recall the definitions of different heat transfer mechanisms.
A) Conduction — Conduction is the process by which heat energy is transmitted through direct contact between neighboring molecules or atoms. When one end of a metal rod is heated, the particles at that end gain kinetic energy and vibrate more vigorously. These vibrating particles collide with adjacent particles, transferring some of their energy, and this process continues along the rod, transferring heat.
The question asks for another name for the First Law of Thermodynamics. This law is a fundamental principle in physics that describes the relationship between heat, work, and internal energy in a system. Understanding its core concept will lead to the correct answer.
Correct Option: A) Energy conservation
The question asks about the Second Law of Thermodynamics. We need to identify the statement that correctly represents this fundamental law of physics. We will analyze each option against the principles of thermodynamics.
Correct Option: A) Heat cannot flow from a colder body to a hotter body spontaneously. This is a direct statement of the Clausius form of the Second Law of Thermodynamics, which defines the direction of spontaneous heat transfer.