Rice cooks quickly in a pressure cooker because high pressure increases the boiling point of water. Under normal atmospheric pressure, water boils at 100°C. However, in a pressure cooker, the sealed environment raises the pressure, which in turn raises the boiling point of water to higher than 100°CRead more
Rice cooks quickly in a pressure cooker because high pressure increases the boiling point of water. Under normal atmospheric pressure, water boils at 100°C. However, in a pressure cooker, the sealed environment raises the pressure, which in turn raises the boiling point of water to higher than 100°C. This allows the water and steam inside the cooker to reach higher temperatures, which accelerates the cooking process. The higher temperature results in faster heat transfer to the rice, softening it more quickly than it would at the normal boiling point. This principle is why pressure cookers are efficient for cooking not only rice but also other foods that benefit from being cooked at higher temperatures and in shorter times. Therefore, the correct answer is [B] High pressure increases the boiling point of water. This understanding is essential for efficient cooking and energy conservation in culinary practices.
Man feels discomfort due to humidity primarily because sweat does not evaporate efficiently in high humidity conditions. Evaporation of sweat from the skin surface is a critical mechanism for cooling the body. In high humidity, the air is already saturated with moisture, significantly slowing down tRead more
Man feels discomfort due to humidity primarily because sweat does not evaporate efficiently in high humidity conditions. Evaporation of sweat from the skin surface is a critical mechanism for cooling the body. In high humidity, the air is already saturated with moisture, significantly slowing down the rate of sweat evaporation. As a result, the body retains more heat, leading to overheating and discomfort. This lack of effective cooling makes the body feel hotter and more uncomfortable compared to dry conditions, where sweat evaporates more readily and provides a cooling effect. Therefore, the correct answer is [C] Sweat not evaporating due to humidity. Understanding this phenomenon is essential for managing heat stress and designing cooling strategies in hot, humid environments, impacting areas such as workplace safety, athletic performance, and general well-being.
When a piece of ice floating in a glass of water completely melts, the level of water in the glass remains unchanged. This phenomenon can be explained by the principle of buoyancy and the displacement of water. A floating ice cube displaces a volume of water equal to the weight of the ice. When theRead more
When a piece of ice floating in a glass of water completely melts, the level of water in the glass remains unchanged. This phenomenon can be explained by the principle of buoyancy and the displacement of water. A floating ice cube displaces a volume of water equal to the weight of the ice. When the ice melts, it turns into water and occupies the same volume that was initially displaced. Since the density of ice is less than that of water, the melted ice, now in liquid form, fills the exact volume it previously displaced. Therefore, the overall water level in the glass does not change. This principle holds true for any ice floating in a liquid, assuming no additional factors such as temperature changes significantly affecting the water’s volume. Hence, the correct answer is [C] remain unchanged. Understanding this concept illustrates fundamental principles of physics and fluid dynamics.
Skating on ice demonstrates that increasing pressure lowers the melting point of ice. When pressure is applied to ice, it causes a temporary phase transition, converting a thin layer of ice into liquid water, even at temperatures below the normal freezing point. This phenomenon reduces friction betwRead more
Skating on ice demonstrates that increasing pressure lowers the melting point of ice. When pressure is applied to ice, it causes a temporary phase transition, converting a thin layer of ice into liquid water, even at temperatures below the normal freezing point. This phenomenon reduces friction between the skate blades and the ice surface, enabling smoother skating movements. Hence, the correct answer is [C] decreases. Understanding this effect is essential in various fields, including sports science, materials engineering, and glaciology.
When two pieces of ice are pressed together, they stick together because the increased pressure lowers the melting point of ice at the point of contact. This phenomenon allows a thin layer of ice to melt, creating a temporary liquid bridge between the pieces. Upon release of pressure, this liquid reRead more
When two pieces of ice are pressed together, they stick together because the increased pressure lowers the melting point of ice at the point of contact. This phenomenon allows a thin layer of ice to melt, creating a temporary liquid bridge between the pieces. Upon release of pressure, this liquid refreezes, binding the pieces together. Therefore, the correct answer is [A] Due to increase in pressure the melting point of ice decreases. Understanding this effect is fundamental in various applications, including ice sculpting, construction, and geology.
During summer days, water kept in an earthen vessel stays cool primarily due to the phenomenon of evaporation. The porous structure of the earthen material allows water to slowly seep through its surface. Once on the outer surface, water molecules evaporate into the air, taking away latent heat fromRead more
During summer days, water kept in an earthen vessel stays cool primarily due to the phenomenon of evaporation. The porous structure of the earthen material allows water to slowly seep through its surface. Once on the outer surface, water molecules evaporate into the air, taking away latent heat from the remaining water inside the vessel. This process continues, leading to a continuous removal of heat from the water, thereby keeping it cool. Unlike other options such as diffusion, transpiration, or osmosis, which involve the movement of substances through membranes or diffusion gradients, evaporation specifically refers to the conversion of liquid water into vapor, usually at the surface of a liquid. Understanding this cooling effect of evaporation is crucial in various contexts, such as traditional cooling methods, climate control strategies, and the design of evaporative cooling systems for buildings or refrigeration units. Therefore, the correct answer is [D] Evaporation.
The process of making camphor vapor from solid camphor is called sublimation. Sublimation is a phase transition where a substance transitions directly from its solid phase to its gas phase without passing through the intermediate liquid phase. When solid camphor is heated, it undergoes sublimation,Read more
The process of making camphor vapor from solid camphor is called sublimation. Sublimation is a phase transition where a substance transitions directly from its solid phase to its gas phase without passing through the intermediate liquid phase. When solid camphor is heated, it undergoes sublimation, releasing vapors that have its characteristic odor. This process is commonly used in various applications, including religious rituals, medicinal purposes, and as a moth repellent. Camphor’s ability to sublime at room temperature also makes it useful in providing aromatic effects in products such as air fresheners and deodorants. Understanding the principle of sublimation is essential not only for utilizing camphor but also for comprehending various other natural and synthetic processes, such as the purification of substances, the functioning of certain air conditioning systems, and the behavior of volatile compounds in the atmosphere. Therefore, the correct answer to the process of making camphor vapor from solid camphor is [D] Sublimation.
Dew is not formed on a strong windy night primarily because the rate of evaporation is fast. Wind increases the movement of air, which in turn enhances the rate of evaporation by carrying away the thin layer of moisture near the ground. As a result, any moisture that condenses on surfaces at night dRead more
Dew is not formed on a strong windy night primarily because the rate of evaporation is fast. Wind increases the movement of air, which in turn enhances the rate of evaporation by carrying away the thin layer of moisture near the ground. As a result, any moisture that condenses on surfaces at night due to cooling temperatures is quickly evaporated by the wind, preventing the formation of dew. This phenomenon is particularly noticeable on windy nights when the air movement is strong enough to disrupt the delicate balance between condensation and evaporation needed for dew formation. Additionally, wind can also mix and disperse the air, reducing the relative humidity near the ground, which further inhibits dew formation. Therefore, the correct answer is [A] the rate of evaporation is fast. Understanding this effect of wind on dew formation is essential in meteorology and agriculture, particularly for predicting overnight condensation and its impact on crops and outdoor activities.
It takes more time to cook potatoes on mountain tops primarily because atmospheric pressure is low. At higher altitudes, such as mountain tops, the atmospheric pressure is lower compared to sea level. This reduced atmospheric pressure lowers the boiling point of water. Since cooking involves boilingRead more
It takes more time to cook potatoes on mountain tops primarily because atmospheric pressure is low. At higher altitudes, such as mountain tops, the atmospheric pressure is lower compared to sea level. This reduced atmospheric pressure lowers the boiling point of water. Since cooking involves boiling water to cook potatoes, the lower boiling point means that water boils at a lower temperature at higher altitudes than it does at sea level. Consequently, the lower temperature requires more time for the potatoes to cook thoroughly. Therefore, despite the temperature at the mountain top potentially being lower than at sea level due to factors like altitude and weather, the crucial factor affecting cooking time is the reduced atmospheric pressure, which affects the boiling point of water and thus the cooking process. Understanding this effect of altitude on cooking times is essential for planning meals and cooking effectively in high-altitude environments.
The reason why snow covered on mountains does not melt simultaneously due to the heat of the Sun is primarily because it reflects most of the heat received from the Sun. Snow has high albedo, meaning it reflects a significant portion of the sunlight that strikes its surface. This reflective propertyRead more
The reason why snow covered on mountains does not melt simultaneously due to the heat of the Sun is primarily because it reflects most of the heat received from the Sun. Snow has high albedo, meaning it reflects a significant portion of the sunlight that strikes its surface. This reflective property prevents snow from absorbing much heat, unlike darker surfaces which absorb more solar radiation. As a result, even when exposed to direct sunlight, the temperature of the snow remains lower, slowing down the melting process. Additionally, the high altitude and cooler air temperatures at mountain peaks also contribute to slower melting. Therefore, the combination of reflective properties and cooler ambient temperatures at higher elevations helps maintain the snow cover on mountain peaks, despite exposure to solar radiation. Understanding these factors is crucial for predicting snowmelt rates, managing water resources, and assessing the impact of climate change on mountain ecosystems.
Rice cooks quickly in a pressure cooker because
Rice cooks quickly in a pressure cooker because high pressure increases the boiling point of water. Under normal atmospheric pressure, water boils at 100°C. However, in a pressure cooker, the sealed environment raises the pressure, which in turn raises the boiling point of water to higher than 100°CRead more
Rice cooks quickly in a pressure cooker because high pressure increases the boiling point of water. Under normal atmospheric pressure, water boils at 100°C. However, in a pressure cooker, the sealed environment raises the pressure, which in turn raises the boiling point of water to higher than 100°C. This allows the water and steam inside the cooker to reach higher temperatures, which accelerates the cooking process. The higher temperature results in faster heat transfer to the rice, softening it more quickly than it would at the normal boiling point. This principle is why pressure cookers are efficient for cooking not only rice but also other foods that benefit from being cooked at higher temperatures and in shorter times. Therefore, the correct answer is [B] High pressure increases the boiling point of water. This understanding is essential for efficient cooking and energy conservation in culinary practices.
See lessMan feels discomfort due to humidity. Which of the following is the appropriate reason for this?
Man feels discomfort due to humidity primarily because sweat does not evaporate efficiently in high humidity conditions. Evaporation of sweat from the skin surface is a critical mechanism for cooling the body. In high humidity, the air is already saturated with moisture, significantly slowing down tRead more
Man feels discomfort due to humidity primarily because sweat does not evaporate efficiently in high humidity conditions. Evaporation of sweat from the skin surface is a critical mechanism for cooling the body. In high humidity, the air is already saturated with moisture, significantly slowing down the rate of sweat evaporation. As a result, the body retains more heat, leading to overheating and discomfort. This lack of effective cooling makes the body feel hotter and more uncomfortable compared to dry conditions, where sweat evaporates more readily and provides a cooling effect. Therefore, the correct answer is [C] Sweat not evaporating due to humidity. Understanding this phenomenon is essential for managing heat stress and designing cooling strategies in hot, humid environments, impacting areas such as workplace safety, athletic performance, and general well-being.
See lessA piece of ice is floating in a glass filled with water. When the piece is completely melted, the level of water in the glass
When a piece of ice floating in a glass of water completely melts, the level of water in the glass remains unchanged. This phenomenon can be explained by the principle of buoyancy and the displacement of water. A floating ice cube displaces a volume of water equal to the weight of the ice. When theRead more
When a piece of ice floating in a glass of water completely melts, the level of water in the glass remains unchanged. This phenomenon can be explained by the principle of buoyancy and the displacement of water. A floating ice cube displaces a volume of water equal to the weight of the ice. When the ice melts, it turns into water and occupies the same volume that was initially displaced. Since the density of ice is less than that of water, the melted ice, now in liquid form, fills the exact volume it previously displaced. Therefore, the overall water level in the glass does not change. This principle holds true for any ice floating in a liquid, assuming no additional factors such as temperature changes significantly affecting the water’s volume. Hence, the correct answer is [C] remain unchanged. Understanding this concept illustrates fundamental principles of physics and fluid dynamics.
See lessSkating on ice shows that on increasing the pressure the melting point of ice
Skating on ice demonstrates that increasing pressure lowers the melting point of ice. When pressure is applied to ice, it causes a temporary phase transition, converting a thin layer of ice into liquid water, even at temperatures below the normal freezing point. This phenomenon reduces friction betwRead more
Skating on ice demonstrates that increasing pressure lowers the melting point of ice. When pressure is applied to ice, it causes a temporary phase transition, converting a thin layer of ice into liquid water, even at temperatures below the normal freezing point. This phenomenon reduces friction between the skate blades and the ice surface, enabling smoother skating movements. Hence, the correct answer is [C] decreases. Understanding this effect is essential in various fields, including sports science, materials engineering, and glaciology.
See lessWhen two pieces of ice are pressed together, the pieces stick together, because —
When two pieces of ice are pressed together, they stick together because the increased pressure lowers the melting point of ice at the point of contact. This phenomenon allows a thin layer of ice to melt, creating a temporary liquid bridge between the pieces. Upon release of pressure, this liquid reRead more
When two pieces of ice are pressed together, they stick together because the increased pressure lowers the melting point of ice at the point of contact. This phenomenon allows a thin layer of ice to melt, creating a temporary liquid bridge between the pieces. Upon release of pressure, this liquid refreezes, binding the pieces together. Therefore, the correct answer is [A] Due to increase in pressure the melting point of ice decreases. Understanding this effect is fundamental in various applications, including ice sculpting, construction, and geology.
See lessDuring summer days, water kept in an earthen vessel cool. This happens due to the following phenomenon
During summer days, water kept in an earthen vessel stays cool primarily due to the phenomenon of evaporation. The porous structure of the earthen material allows water to slowly seep through its surface. Once on the outer surface, water molecules evaporate into the air, taking away latent heat fromRead more
During summer days, water kept in an earthen vessel stays cool primarily due to the phenomenon of evaporation. The porous structure of the earthen material allows water to slowly seep through its surface. Once on the outer surface, water molecules evaporate into the air, taking away latent heat from the remaining water inside the vessel. This process continues, leading to a continuous removal of heat from the water, thereby keeping it cool. Unlike other options such as diffusion, transpiration, or osmosis, which involve the movement of substances through membranes or diffusion gradients, evaporation specifically refers to the conversion of liquid water into vapor, usually at the surface of a liquid. Understanding this cooling effect of evaporation is crucial in various contexts, such as traditional cooling methods, climate control strategies, and the design of evaporative cooling systems for buildings or refrigeration units. Therefore, the correct answer is [D] Evaporation.
See lessThe process of making camphor vapor from solid camphor is called
The process of making camphor vapor from solid camphor is called sublimation. Sublimation is a phase transition where a substance transitions directly from its solid phase to its gas phase without passing through the intermediate liquid phase. When solid camphor is heated, it undergoes sublimation,Read more
The process of making camphor vapor from solid camphor is called sublimation. Sublimation is a phase transition where a substance transitions directly from its solid phase to its gas phase without passing through the intermediate liquid phase. When solid camphor is heated, it undergoes sublimation, releasing vapors that have its characteristic odor. This process is commonly used in various applications, including religious rituals, medicinal purposes, and as a moth repellent. Camphor’s ability to sublime at room temperature also makes it useful in providing aromatic effects in products such as air fresheners and deodorants. Understanding the principle of sublimation is essential not only for utilizing camphor but also for comprehending various other natural and synthetic processes, such as the purification of substances, the functioning of certain air conditioning systems, and the behavior of volatile compounds in the atmosphere. Therefore, the correct answer to the process of making camphor vapor from solid camphor is [D] Sublimation.
See lessDew is not formed on a strong windy night because
Dew is not formed on a strong windy night primarily because the rate of evaporation is fast. Wind increases the movement of air, which in turn enhances the rate of evaporation by carrying away the thin layer of moisture near the ground. As a result, any moisture that condenses on surfaces at night dRead more
Dew is not formed on a strong windy night primarily because the rate of evaporation is fast. Wind increases the movement of air, which in turn enhances the rate of evaporation by carrying away the thin layer of moisture near the ground. As a result, any moisture that condenses on surfaces at night due to cooling temperatures is quickly evaporated by the wind, preventing the formation of dew. This phenomenon is particularly noticeable on windy nights when the air movement is strong enough to disrupt the delicate balance between condensation and evaporation needed for dew formation. Additionally, wind can also mix and disperse the air, reducing the relative humidity near the ground, which further inhibits dew formation. Therefore, the correct answer is [A] the rate of evaporation is fast. Understanding this effect of wind on dew formation is essential in meteorology and agriculture, particularly for predicting overnight condensation and its impact on crops and outdoor activities.
See lessIt takes more time to cook potatoes on mountain tops because
It takes more time to cook potatoes on mountain tops primarily because atmospheric pressure is low. At higher altitudes, such as mountain tops, the atmospheric pressure is lower compared to sea level. This reduced atmospheric pressure lowers the boiling point of water. Since cooking involves boilingRead more
It takes more time to cook potatoes on mountain tops primarily because atmospheric pressure is low. At higher altitudes, such as mountain tops, the atmospheric pressure is lower compared to sea level. This reduced atmospheric pressure lowers the boiling point of water. Since cooking involves boiling water to cook potatoes, the lower boiling point means that water boils at a lower temperature at higher altitudes than it does at sea level. Consequently, the lower temperature requires more time for the potatoes to cook thoroughly. Therefore, despite the temperature at the mountain top potentially being lower than at sea level due to factors like altitude and weather, the crucial factor affecting cooking time is the reduced atmospheric pressure, which affects the boiling point of water and thus the cooking process. Understanding this effect of altitude on cooking times is essential for planning meals and cooking effectively in high-altitude environments.
See lessThe reason why the snow covered on the mountains does not melt simultaneously due to the heat of the Sun is
The reason why snow covered on mountains does not melt simultaneously due to the heat of the Sun is primarily because it reflects most of the heat received from the Sun. Snow has high albedo, meaning it reflects a significant portion of the sunlight that strikes its surface. This reflective propertyRead more
The reason why snow covered on mountains does not melt simultaneously due to the heat of the Sun is primarily because it reflects most of the heat received from the Sun. Snow has high albedo, meaning it reflects a significant portion of the sunlight that strikes its surface. This reflective property prevents snow from absorbing much heat, unlike darker surfaces which absorb more solar radiation. As a result, even when exposed to direct sunlight, the temperature of the snow remains lower, slowing down the melting process. Additionally, the high altitude and cooler air temperatures at mountain peaks also contribute to slower melting. Therefore, the combination of reflective properties and cooler ambient temperatures at higher elevations helps maintain the snow cover on mountain peaks, despite exposure to solar radiation. Understanding these factors is crucial for predicting snowmelt rates, managing water resources, and assessing the impact of climate change on mountain ecosystems.
See less