A glass of water does not change into ice at 0°C because, for the water to freeze, some amount of heat must be removed from it. Freezing is a phase transition from liquid to solid that occurs when the temperature of the substance decreases to its freezing point. At 0°C, the water reaches its freezinRead more
A glass of water does not change into ice at 0°C because, for the water to freeze, some amount of heat must be removed from it. Freezing is a phase transition from liquid to solid that occurs when the temperature of the substance decreases to its freezing point. At 0°C, the water reaches its freezing point, but freezing does not occur until enough heat energy is removed to lower the temperature below this point.
This process of heat removal is necessary to break the intermolecular bonds between water molecules, allowing them to arrange into a crystalline structure characteristic of ice. Until sufficient heat is removed, the water remains in its liquid state, even at the freezing point. Therefore, the correct answer is [C] To freeze the water in the glass, some amount of heat is necessary to be removed from it.
The process responsible for keeping the water cold in the pitcher is evaporation. Evaporation is the phase transition from liquid to gas that occurs at the surface of the water, where molecules gain enough energy to escape into the air. As water molecules evaporate, they take away heat energy from tRead more
The process responsible for keeping the water cold in the pitcher is evaporation. Evaporation is the phase transition from liquid to gas that occurs at the surface of the water, where molecules gain enough energy to escape into the air. As water molecules evaporate, they take away heat energy from the remaining water, thereby cooling it down.
This cooling effect is due to the principle of latent heat, where energy is absorbed or released during a phase transition without a change in temperature. In this case, the absorbed heat energy is used to break the intermolecular bonds between water molecules, allowing them to escape into the air as vapor. The remaining water loses heat energy, resulting in a decrease in temperature and the sensation of coldness. Therefore, the correct answer is [B] Evaporation.
The correct statement is [A] Absolute humidity is expressed in grams per cubic meter of air. Absolute humidity represents the actual amount of water vapor present in a unit volume of air, usually measured in grams per cubic meter (g/m³). This measurement provides a direct indication of the moistureRead more
The correct statement is [A] Absolute humidity is expressed in grams per cubic meter of air. Absolute humidity represents the actual amount of water vapor present in a unit volume of air, usually measured in grams per cubic meter (g/m³). This measurement provides a direct indication of the moisture content of the air, which is essential for various applications in meteorology, engineering, and agriculture.
Options B, C, and D are incorrect. Temperature generally decreases with altitude at a rate of approximately 9.8°C per 1000 meters (not 165 meters) due to the lapse rate in the Earth’s atmosphere (B). With an increase in air temperature, the capacity of air to hold moisture actually increases, not reduces (C). An increase in temperature typically leads to a decrease in air pressure, not the opposite (D).
The time taken for the hot water to cool from 80°C to 70°C will be more than 10 minutes. According to Newton's law of cooling, the rate of cooling is proportional to the temperature difference between the body and its surroundings. As the temperature difference decreases, the rate of cooling also deRead more
The time taken for the hot water to cool from 80°C to 70°C will be more than 10 minutes. According to Newton’s law of cooling, the rate of cooling is proportional to the temperature difference between the body and its surroundings. As the temperature difference decreases, the rate of cooling also decreases.
In the given scenario, the water cools from 90°C to 80°C in 10 minutes. This means the average temperature during this interval is 85°C, which is 60°C above the surrounding temperature. When the water cools from 80°C to 70°C, the average temperature is 75°C, which is 50°C above the surroundings. Since the temperature difference is lower, the rate of cooling will be slower, and it will take more than 10 minutes for the water to cool through this 10°C interval.
Therefore, the correct answer is [C] More than 10 minutes.
Newton's cooling law is applicable only when [A] the difference in temperature is not very much. This law describes the rate of cooling of an object in relation to the temperature difference between the object and its surroundings. It assumes that the temperature difference is small enough to maintaRead more
Newton’s cooling law is applicable only when [A] the difference in temperature is not very much. This law describes the rate of cooling of an object in relation to the temperature difference between the object and its surroundings. It assumes that the temperature difference is small enough to maintain a linear relationship between the rate of cooling and the temperature difference. However, if the temperature difference is very large, nonlinear effects such as convection currents and radiation become more significant, and Newton’s law of cooling may not accurately describe the cooling process. Therefore, it is most applicable when the temperature difference is relatively small, allowing for a linear approximation of the cooling rate. Options [B], [C], and [D] are incorrect as they do not accurately describe the conditions under which Newton’s cooling law applies.
A glass of water does not change into ice at 0 °C. What is the reason for this?
A glass of water does not change into ice at 0°C because, for the water to freeze, some amount of heat must be removed from it. Freezing is a phase transition from liquid to solid that occurs when the temperature of the substance decreases to its freezing point. At 0°C, the water reaches its freezinRead more
A glass of water does not change into ice at 0°C because, for the water to freeze, some amount of heat must be removed from it. Freezing is a phase transition from liquid to solid that occurs when the temperature of the substance decreases to its freezing point. At 0°C, the water reaches its freezing point, but freezing does not occur until enough heat energy is removed to lower the temperature below this point.
This process of heat removal is necessary to break the intermolecular bonds between water molecules, allowing them to arrange into a crystalline structure characteristic of ice. Until sufficient heat is removed, the water remains in its liquid state, even at the freezing point. Therefore, the correct answer is [C] To freeze the water in the glass, some amount of heat is necessary to be removed from it.
See lessDue to which of the following processes the water remains cold in the pitcher?
The process responsible for keeping the water cold in the pitcher is evaporation. Evaporation is the phase transition from liquid to gas that occurs at the surface of the water, where molecules gain enough energy to escape into the air. As water molecules evaporate, they take away heat energy from tRead more
The process responsible for keeping the water cold in the pitcher is evaporation. Evaporation is the phase transition from liquid to gas that occurs at the surface of the water, where molecules gain enough energy to escape into the air. As water molecules evaporate, they take away heat energy from the remaining water, thereby cooling it down.
This cooling effect is due to the principle of latent heat, where energy is absorbed or released during a phase transition without a change in temperature. In this case, the absorbed heat energy is used to break the intermolecular bonds between water molecules, allowing them to escape into the air as vapor. The remaining water loses heat energy, resulting in a decrease in temperature and the sensation of coldness. Therefore, the correct answer is [B] Evaporation.
See lessWhich of the following statements is correct?
The correct statement is [A] Absolute humidity is expressed in grams per cubic meter of air. Absolute humidity represents the actual amount of water vapor present in a unit volume of air, usually measured in grams per cubic meter (g/m³). This measurement provides a direct indication of the moistureRead more
The correct statement is [A] Absolute humidity is expressed in grams per cubic meter of air. Absolute humidity represents the actual amount of water vapor present in a unit volume of air, usually measured in grams per cubic meter (g/m³). This measurement provides a direct indication of the moisture content of the air, which is essential for various applications in meteorology, engineering, and agriculture.
Options B, C, and D are incorrect. Temperature generally decreases with altitude at a rate of approximately 9.8°C per 1000 meters (not 165 meters) due to the lapse rate in the Earth’s atmosphere (B). With an increase in air temperature, the capacity of air to hold moisture actually increases, not reduces (C). An increase in temperature typically leads to a decrease in air pressure, not the opposite (D).
See lessIf hot water takes 10 minutes to cool from 90°C to 80°C, then the time taken to cool from 80°C to 70°C is
The time taken for the hot water to cool from 80°C to 70°C will be more than 10 minutes. According to Newton's law of cooling, the rate of cooling is proportional to the temperature difference between the body and its surroundings. As the temperature difference decreases, the rate of cooling also deRead more
The time taken for the hot water to cool from 80°C to 70°C will be more than 10 minutes. According to Newton’s law of cooling, the rate of cooling is proportional to the temperature difference between the body and its surroundings. As the temperature difference decreases, the rate of cooling also decreases.
See lessIn the given scenario, the water cools from 90°C to 80°C in 10 minutes. This means the average temperature during this interval is 85°C, which is 60°C above the surrounding temperature. When the water cools from 80°C to 70°C, the average temperature is 75°C, which is 50°C above the surroundings. Since the temperature difference is lower, the rate of cooling will be slower, and it will take more than 10 minutes for the water to cool through this 10°C interval.
Therefore, the correct answer is [C] More than 10 minutes.
Newton’s cooling law is applicable only when
Newton's cooling law is applicable only when [A] the difference in temperature is not very much. This law describes the rate of cooling of an object in relation to the temperature difference between the object and its surroundings. It assumes that the temperature difference is small enough to maintaRead more
Newton’s cooling law is applicable only when [A] the difference in temperature is not very much. This law describes the rate of cooling of an object in relation to the temperature difference between the object and its surroundings. It assumes that the temperature difference is small enough to maintain a linear relationship between the rate of cooling and the temperature difference. However, if the temperature difference is very large, nonlinear effects such as convection currents and radiation become more significant, and Newton’s law of cooling may not accurately describe the cooling process. Therefore, it is most applicable when the temperature difference is relatively small, allowing for a linear approximation of the cooling rate. Options [B], [C], and [D] are incorrect as they do not accurately describe the conditions under which Newton’s cooling law applies.
See less