The room can be cooled effectively by releasing compressed gas. When compressed gas is released into a room, it undergoes expansion. This expansion process absorbs heat from the surrounding environment due to the endothermic nature of gas expansion, thereby cooling the air in the room. This principlRead more
The room can be cooled effectively by releasing compressed gas. When compressed gas is released into a room, it undergoes expansion. This expansion process absorbs heat from the surrounding environment due to the endothermic nature of gas expansion, thereby cooling the air in the room. This principle is the foundation of air conditioning and refrigeration systems. As the compressed gas expands, it absorbs thermal energy from the room’s air, resulting in a drop in temperature. The cooling effect is utilized in various cooling devices, such as air conditioners and refrigerators, where the refrigerant gas cycles through compression and expansion phases to maintain a cool environment. This method of cooling is efficient and widely used in residential, commercial, and industrial applications. Therefore, the correct answer is [B] by releasing compressed gas.
Running a fan in hot weather provides comfort primarily because it enhances the evaporation of sweat from our skin. When the air moves over the skin, it increases the rate at which sweat evaporates. This process, known as evaporative cooling, helps to cool the body as the phase change from liquid swRead more
Running a fan in hot weather provides comfort primarily because it enhances the evaporation of sweat from our skin. When the air moves over the skin, it increases the rate at which sweat evaporates. This process, known as evaporative cooling, helps to cool the body as the phase change from liquid sweat to vapor absorbs heat from the skin, lowering the body’s temperature. The fan does not produce cool air but rather circulates the existing air, making it feel cooler due to the increased evaporation rate. This effect is crucial for maintaining a comfortable body temperature in hot weather, as efficient evaporation is a key mechanism for heat regulation in humans. Therefore, the primary reason a fan provides comfort in hot weather is that our sweat evaporates faster, making the correct answer [B] Our sweat evaporates faster.
When salt is added to water, it affects the water's boiling and freezing points due to colligative properties. These properties depend on the number of solute particles in a solution, not their identity. The addition of salt (a solute) to water (the solvent) causes two significant changes: the boiliRead more
When salt is added to water, it affects the water’s boiling and freezing points due to colligative properties. These properties depend on the number of solute particles in a solution, not their identity. The addition of salt (a solute) to water (the solvent) causes two significant changes: the boiling point increases, and the freezing point decreases. This happens because the salt ions disrupt the formation of a solid lattice structure, making it harder for water to freeze, thus lowering the freezing point (a phenomenon known as freezing point depression). Simultaneously, the presence of salt raises the boiling point because it requires additional energy (heat) to break the interactions between the water molecules and the dissolved salt ions, leading to boiling point elevation. Therefore, the correct answer is [A] Boiling point increases and freezing point decreases.
The temperature of the Sun's surface, known as the photosphere, is approximately 6000K. The photosphere is the outer layer of the Sun that emits the light visible from Earth. This temperature is critical for understanding various solar phenomena, including the spectrum of light the Sun emits and itsRead more
The temperature of the Sun’s surface, known as the photosphere, is approximately 6000K. The photosphere is the outer layer of the Sun that emits the light visible from Earth. This temperature is critical for understanding various solar phenomena, including the spectrum of light the Sun emits and its interactions with Earth’s atmosphere. The photosphere’s temperature influences the color of the Sun, appearing as a bright, yellowish-white light due to its black-body radiation spectrum. Understanding this temperature helps astronomers study the Sun’s structure, energy output, and the processes driving solar activities such as sunspots and solar flares. Thus, the temperature of the Sun’s surface is best represented by the value 6000K, making the correct answer [C] 6000K.
The first law of thermodynamics, also known as the law of energy conservation, confirms the concept of energy conservation. This fundamental principle states that energy within an isolated system remains constant, implying that energy cannot be created or destroyed but can only change forms. For exaRead more
The first law of thermodynamics, also known as the law of energy conservation, confirms the concept of energy conservation. This fundamental principle states that energy within an isolated system remains constant, implying that energy cannot be created or destroyed but can only change forms. For example, during thermodynamic processes, energy can be transformed from heat to work or stored as internal energy within the system. The total energy input to a system, considering both heat and work, equals the change in the system’s internal energy. This law underpins the conservation of energy in all physical processes, providing a foundational framework for understanding energy transformations in various scientific and engineering contexts. It ensures that, regardless of the process, the total energy before and after remains the same. Thus, the first law of thermodynamics explicitly confirms the concept of energy conservation, making the correct answer [A] Energy conservation.
The room can be cooled by
The room can be cooled effectively by releasing compressed gas. When compressed gas is released into a room, it undergoes expansion. This expansion process absorbs heat from the surrounding environment due to the endothermic nature of gas expansion, thereby cooling the air in the room. This principlRead more
The room can be cooled effectively by releasing compressed gas. When compressed gas is released into a room, it undergoes expansion. This expansion process absorbs heat from the surrounding environment due to the endothermic nature of gas expansion, thereby cooling the air in the room. This principle is the foundation of air conditioning and refrigeration systems. As the compressed gas expands, it absorbs thermal energy from the room’s air, resulting in a drop in temperature. The cooling effect is utilized in various cooling devices, such as air conditioners and refrigerators, where the refrigerant gas cycles through compression and expansion phases to maintain a cool environment. This method of cooling is efficient and widely used in residential, commercial, and industrial applications. Therefore, the correct answer is [B] by releasing compressed gas.
See lessRunning a fan in hot weather gives comfort because
Running a fan in hot weather provides comfort primarily because it enhances the evaporation of sweat from our skin. When the air moves over the skin, it increases the rate at which sweat evaporates. This process, known as evaporative cooling, helps to cool the body as the phase change from liquid swRead more
Running a fan in hot weather provides comfort primarily because it enhances the evaporation of sweat from our skin. When the air moves over the skin, it increases the rate at which sweat evaporates. This process, known as evaporative cooling, helps to cool the body as the phase change from liquid sweat to vapor absorbs heat from the skin, lowering the body’s temperature. The fan does not produce cool air but rather circulates the existing air, making it feel cooler due to the increased evaporation rate. This effect is crucial for maintaining a comfortable body temperature in hot weather, as efficient evaporation is a key mechanism for heat regulation in humans. Therefore, the primary reason a fan provides comfort in hot weather is that our sweat evaporates faster, making the correct answer [B] Our sweat evaporates faster.
See lessWhen salt is added to water, which of the following changes takes place?
When salt is added to water, it affects the water's boiling and freezing points due to colligative properties. These properties depend on the number of solute particles in a solution, not their identity. The addition of salt (a solute) to water (the solvent) causes two significant changes: the boiliRead more
When salt is added to water, it affects the water’s boiling and freezing points due to colligative properties. These properties depend on the number of solute particles in a solution, not their identity. The addition of salt (a solute) to water (the solvent) causes two significant changes: the boiling point increases, and the freezing point decreases. This happens because the salt ions disrupt the formation of a solid lattice structure, making it harder for water to freeze, thus lowering the freezing point (a phenomenon known as freezing point depression). Simultaneously, the presence of salt raises the boiling point because it requires additional energy (heat) to break the interactions between the water molecules and the dissolved salt ions, leading to boiling point elevation. Therefore, the correct answer is [A] Boiling point increases and freezing point decreases.
See lessThe temperature of the Sun’s surface is
The temperature of the Sun's surface, known as the photosphere, is approximately 6000K. The photosphere is the outer layer of the Sun that emits the light visible from Earth. This temperature is critical for understanding various solar phenomena, including the spectrum of light the Sun emits and itsRead more
The temperature of the Sun’s surface, known as the photosphere, is approximately 6000K. The photosphere is the outer layer of the Sun that emits the light visible from Earth. This temperature is critical for understanding various solar phenomena, including the spectrum of light the Sun emits and its interactions with Earth’s atmosphere. The photosphere’s temperature influences the color of the Sun, appearing as a bright, yellowish-white light due to its black-body radiation spectrum. Understanding this temperature helps astronomers study the Sun’s structure, energy output, and the processes driving solar activities such as sunspots and solar flares. Thus, the temperature of the Sun’s surface is best represented by the value 6000K, making the correct answer [C] 6000K.
See lessWhich concept does the first law of thermodynamics confirm?
The first law of thermodynamics, also known as the law of energy conservation, confirms the concept of energy conservation. This fundamental principle states that energy within an isolated system remains constant, implying that energy cannot be created or destroyed but can only change forms. For exaRead more
The first law of thermodynamics, also known as the law of energy conservation, confirms the concept of energy conservation. This fundamental principle states that energy within an isolated system remains constant, implying that energy cannot be created or destroyed but can only change forms. For example, during thermodynamic processes, energy can be transformed from heat to work or stored as internal energy within the system. The total energy input to a system, considering both heat and work, equals the change in the system’s internal energy. This law underpins the conservation of energy in all physical processes, providing a foundational framework for understanding energy transformations in various scientific and engineering contexts. It ensures that, regardless of the process, the total energy before and after remains the same. Thus, the first law of thermodynamics explicitly confirms the concept of energy conservation, making the correct answer [A] Energy conservation.
See less