There is no atmosphere on the Moon because its escape velocity is less than the root mean square velocity of atoms; option [D]. This means that gas molecules on the Moon can easily escape into space due to insufficient gravitational pull. Consequently, over time, the Moon lost its atmosphere, resultRead more
There is no atmosphere on the Moon because its escape velocity is less than the root mean square velocity of atoms; option [D]. This means that gas molecules on the Moon can easily escape into space due to insufficient gravitational pull. Consequently, over time, the Moon lost its atmosphere, resulting in its current lack of significant atmospheric gases. This phenomenon contrasts with Earth, which has a sufficiently strong gravitational pull to retain its atmosphere. The Moon’s proximity to the Earth or its revolution around the Sun doesn’t directly affect its lack of atmosphere. While sunlight does reach the Moon, the absence of a significant atmosphere prevents it from creating conditions conducive to atmospheric processes like those on Earth. Therefore, the correct option is [D] Here the escape velocity of atoms is less than their root mean square velocity, elucidating the fundamental reason for the Moon’s lack of atmosphere.
One Horse Power (H.P) is equal to 746 watts; option [C]. This conversion factor is crucial in engineering and physics, especially in determining the power output of engines, motors, and other mechanical devices. It originates from the work of James Watt, who developed the concept of horsepower to coRead more
One Horse Power (H.P) is equal to 746 watts; option [C]. This conversion factor is crucial in engineering and physics, especially in determining the power output of engines, motors, and other mechanical devices. It originates from the work of James Watt, who developed the concept of horsepower to compare the power of steam engines to that of draft horses. Over time, it became a standard unit of power measurement globally. Option [C] 746 watts accurately represents this conversion factor, highlighting the significant relationship between horsepower and watts in quantifying mechanical power. This conversion facilitates efficient communication and calculation in various fields, ensuring consistency and accuracy in power measurements across different systems and applications.
A runner runs for some distance before taking a long jump because the inertia of his body helps him cover more distance during the jump; option [C]. Running increases the momentum of his body, enabling him to generate more force and velocity, which translates into greater distance during the jump. TRead more
A runner runs for some distance before taking a long jump because the inertia of his body helps him cover more distance during the jump; option [C]. Running increases the momentum of his body, enabling him to generate more force and velocity, which translates into greater distance during the jump. Therefore, the correct option is [C] While jumping, the inertia of his body helps him to cover more distance. This strategy is commonly employed in long jump events to maximize the distance achieved, utilizing the momentum gained from running to propel the body further through the air during the jump. It optimizes the athlete’s performance by harnessing the principles of physics, specifically inertia, to enhance the effectiveness of the jump and achieve greater distances.
When two stones of different masses are dropped simultaneously from the top of a building, both stones reach the ground together; option [C]. This phenomenon occurs due to the absence of significant air resistance, and according to the principle of universal gravitation, all objects fall at the sameRead more
When two stones of different masses are dropped simultaneously from the top of a building, both stones reach the ground together; option [C]. This phenomenon occurs due to the absence of significant air resistance, and according to the principle of universal gravitation, all objects fall at the same rate regardless of their mass. Therefore, neither the smaller nor the larger stone reaches the ground before the other. The composition of the stone does not affect this outcome. This concept is a fundamental principle in physics known as the equivalence principle, which states that in a vacuum, all objects experience the same acceleration due to gravity regardless of their mass. Thus, the correct option is [C] Both the stones reach the ground together, illustrating a fundamental aspect of gravitational physics.
Mercury has the lowest density among the listed liquids; option [D]. Mercury's density is approximately 13.6 grams per cubic centimeter (g/cm³), making it much denser than the other options. Clean water typically has a density around 1 g/cm³, while salty water, which contains dissolved salts, may haRead more
Mercury has the lowest density among the listed liquids; option [D]. Mercury’s density is approximately 13.6 grams per cubic centimeter (g/cm³), making it much denser than the other options. Clean water typically has a density around 1 g/cm³, while salty water, which contains dissolved salts, may have a slightly higher density due to the added solutes. Petrol, a liquid hydrocarbon mixture used as fuel, has a density generally lower than water but higher than mercury. However, even petrol’s density is significantly higher than that of mercury. Mercury’s low density is attributed to its atomic structure, consisting of relatively large and heavy atoms closely packed together. This density difference is why mercury sinks when mixed with water, as water has a lower density. Therefore, when comparing the densities of clean water, salty water, petrol, and mercury, mercury has the lowest density, making it unique among the options provided. Thus, the correct option is [D] Mercury.
Bernoulli's theorem is based on energy conservation; option [B]. It states that in a flowing fluid, the total mechanical energy per unit mass remains constant along a streamline. This principle describes the relationship between fluid velocity, pressure, and elevation and is fundamental in fluid dynRead more
Bernoulli’s theorem is based on energy conservation; option [B]. It states that in a flowing fluid, the total mechanical energy per unit mass remains constant along a streamline. This principle describes the relationship between fluid velocity, pressure, and elevation and is fundamental in fluid dynamics, aerodynamics, and hydrodynamics. Bernoulli’s theorem helps analyze fluid flow in various engineering applications, including aircraft design, pipe flow, and hydraulic systems. It is derived from the conservation of energy principle, where the total energy of a system remains constant unless acted upon by external forces. Therefore, the correct option is [B] Energy conservation, elucidating the foundational principle upon which Bernoulli’s theorem is based.
An iron needle floats on the surface of water due to surface tension; option [B]. Surface tension arises from the cohesive forces between water molecules, particularly at the water-air interface. This cohesion creates a thin film on the water's surface with higher tension than the bulk of the liquidRead more
An iron needle floats on the surface of water due to surface tension; option [B]. Surface tension arises from the cohesive forces between water molecules, particularly at the water-air interface. This cohesion creates a thin film on the water’s surface with higher tension than the bulk of the liquid. The surface tension acts like a “skin,” supporting lightweight objects such as the iron needle, allowing it to float. Unlike other materials, the iron needle’s density is higher than that of water, so it would typically sink. However, the strong surface tension of water counteracts the needle’s weight, effectively “holding it up” on the water’s surface. This phenomenon is observed in various contexts, from small insects walking on water to certain lightweight objects floating. Therefore, the correct option is [B] Due to surface tension, as it is the cohesive force at the water’s surface that enables the iron needle to float rather than sink.
Absorption of ink by blotting paper involves the capillary reaction phenomenon; option [B]. Capillary action occurs due to the cohesive and adhesive forces between the liquid molecules and the fibers of the paper. This interaction causes the ink to be drawn upward through the small pores in the papeRead more
Absorption of ink by blotting paper involves the capillary reaction phenomenon; option [B]. Capillary action occurs due to the cohesive and adhesive forces between the liquid molecules and the fibers of the paper. This interaction causes the ink to be drawn upward through the small pores in the paper, facilitating its absorption. Capillary action is crucial in processes like ink absorption in blotting paper, where it efficiently pulls the ink into the paper fibers. Viscosity of the ink refers to its resistance to flow and is not directly related to the adsorption process. Diffusion of ink through blotting involves the movement of ink molecules through the paper, which is not the primary mechanism in ink absorption by blotting paper. Siphon action requires a continuous flow of liquid, which is not applicable to the absorption of ink by blotting paper. Therefore, the correct option is [B] Capillary Reaction phenomenon.
Action and reaction have the same magnitude and opposite directions; option [D]. According to Newton's third law of motion, when one object exerts a force on another object (action), the second object exerts an equal but opposite force on the first object (reaction). These forces act on different obRead more
Action and reaction have the same magnitude and opposite directions; option [D]. According to Newton’s third law of motion, when one object exerts a force on another object (action), the second object exerts an equal but opposite force on the first object (reaction). These forces act on different objects, have equal magnitudes, and opposite directions. Therefore, all options are correct: [A] Work on two different objects, [B] Have the same magnitude, and [C] Have opposite directions. This fundamental principle of action and reaction is essential in understanding the dynamics of interactions between objects and is applicable in various fields of physics and engineering. It elucidates how forces are transmitted between objects and plays a critical role in analyzing and predicting the motion of systems governed by Newtonian mechanics.
To cover the maximum horizontal distance, a ball should be thrown at a 45° angle from the horizontal; option [D]. At this angle, the horizontal and vertical components of the initial velocity are equal, leading to the greatest range for a projectile launched with the same initial speed. Therefore, tRead more
To cover the maximum horizontal distance, a ball should be thrown at a 45° angle from the horizontal; option [D]. At this angle, the horizontal and vertical components of the initial velocity are equal, leading to the greatest range for a projectile launched with the same initial speed. Therefore, the correct option is [D] 45°. This principle is derived from the equations of projectile motion and is applicable in various contexts, from sports like basketball and javelin throwing to engineering applications such as projectile motion calculations. Understanding the optimal launch angle for maximum range is essential for achieving desired distances in projectile motion scenarios, making it a fundamental concept in physics and practical applications. Thus, launching the ball at a 45° angle ensures it travels the farthest horizontally compared to other angles listed.
There is no atmosphere on the Moon, because
There is no atmosphere on the Moon because its escape velocity is less than the root mean square velocity of atoms; option [D]. This means that gas molecules on the Moon can easily escape into space due to insufficient gravitational pull. Consequently, over time, the Moon lost its atmosphere, resultRead more
There is no atmosphere on the Moon because its escape velocity is less than the root mean square velocity of atoms; option [D]. This means that gas molecules on the Moon can easily escape into space due to insufficient gravitational pull. Consequently, over time, the Moon lost its atmosphere, resulting in its current lack of significant atmospheric gases. This phenomenon contrasts with Earth, which has a sufficiently strong gravitational pull to retain its atmosphere. The Moon’s proximity to the Earth or its revolution around the Sun doesn’t directly affect its lack of atmosphere. While sunlight does reach the Moon, the absence of a significant atmosphere prevents it from creating conditions conducive to atmospheric processes like those on Earth. Therefore, the correct option is [D] Here the escape velocity of atoms is less than their root mean square velocity, elucidating the fundamental reason for the Moon’s lack of atmosphere.
See lessOne Horse Power (H.P) is equal to how many watts?
One Horse Power (H.P) is equal to 746 watts; option [C]. This conversion factor is crucial in engineering and physics, especially in determining the power output of engines, motors, and other mechanical devices. It originates from the work of James Watt, who developed the concept of horsepower to coRead more
One Horse Power (H.P) is equal to 746 watts; option [C]. This conversion factor is crucial in engineering and physics, especially in determining the power output of engines, motors, and other mechanical devices. It originates from the work of James Watt, who developed the concept of horsepower to compare the power of steam engines to that of draft horses. Over time, it became a standard unit of power measurement globally. Option [C] 746 watts accurately represents this conversion factor, highlighting the significant relationship between horsepower and watts in quantifying mechanical power. This conversion facilitates efficient communication and calculation in various fields, ensuring consistency and accuracy in power measurements across different systems and applications.
See lessA runner runs for some distance before taking a long jump, because
A runner runs for some distance before taking a long jump because the inertia of his body helps him cover more distance during the jump; option [C]. Running increases the momentum of his body, enabling him to generate more force and velocity, which translates into greater distance during the jump. TRead more
A runner runs for some distance before taking a long jump because the inertia of his body helps him cover more distance during the jump; option [C]. Running increases the momentum of his body, enabling him to generate more force and velocity, which translates into greater distance during the jump. Therefore, the correct option is [C] While jumping, the inertia of his body helps him to cover more distance. This strategy is commonly employed in long jump events to maximize the distance achieved, utilizing the momentum gained from running to propel the body further through the air during the jump. It optimizes the athlete’s performance by harnessing the principles of physics, specifically inertia, to enhance the effectiveness of the jump and achieve greater distances.
See lessTwo stones of different masses are dropped simultaneously from the top of a building
When two stones of different masses are dropped simultaneously from the top of a building, both stones reach the ground together; option [C]. This phenomenon occurs due to the absence of significant air resistance, and according to the principle of universal gravitation, all objects fall at the sameRead more
When two stones of different masses are dropped simultaneously from the top of a building, both stones reach the ground together; option [C]. This phenomenon occurs due to the absence of significant air resistance, and according to the principle of universal gravitation, all objects fall at the same rate regardless of their mass. Therefore, neither the smaller nor the larger stone reaches the ground before the other. The composition of the stone does not affect this outcome. This concept is a fundamental principle in physics known as the equivalence principle, which states that in a vacuum, all objects experience the same acceleration due to gravity regardless of their mass. Thus, the correct option is [C] Both the stones reach the ground together, illustrating a fundamental aspect of gravitational physics.
See lessWhich of the following liquids has the lowest density?
Mercury has the lowest density among the listed liquids; option [D]. Mercury's density is approximately 13.6 grams per cubic centimeter (g/cm³), making it much denser than the other options. Clean water typically has a density around 1 g/cm³, while salty water, which contains dissolved salts, may haRead more
Mercury has the lowest density among the listed liquids; option [D]. Mercury’s density is approximately 13.6 grams per cubic centimeter (g/cm³), making it much denser than the other options. Clean water typically has a density around 1 g/cm³, while salty water, which contains dissolved salts, may have a slightly higher density due to the added solutes. Petrol, a liquid hydrocarbon mixture used as fuel, has a density generally lower than water but higher than mercury. However, even petrol’s density is significantly higher than that of mercury. Mercury’s low density is attributed to its atomic structure, consisting of relatively large and heavy atoms closely packed together. This density difference is why mercury sinks when mixed with water, as water has a lower density. Therefore, when comparing the densities of clean water, salty water, petrol, and mercury, mercury has the lowest density, making it unique among the options provided. Thus, the correct option is [D] Mercury.
See lessBernoulli’s theorem is based on
Bernoulli's theorem is based on energy conservation; option [B]. It states that in a flowing fluid, the total mechanical energy per unit mass remains constant along a streamline. This principle describes the relationship between fluid velocity, pressure, and elevation and is fundamental in fluid dynRead more
Bernoulli’s theorem is based on energy conservation; option [B]. It states that in a flowing fluid, the total mechanical energy per unit mass remains constant along a streamline. This principle describes the relationship between fluid velocity, pressure, and elevation and is fundamental in fluid dynamics, aerodynamics, and hydrodynamics. Bernoulli’s theorem helps analyze fluid flow in various engineering applications, including aircraft design, pipe flow, and hydraulic systems. It is derived from the conservation of energy principle, where the total energy of a system remains constant unless acted upon by external forces. Therefore, the correct option is [B] Energy conservation, elucidating the foundational principle upon which Bernoulli’s theorem is based.
See lessWhy does an iron needle float on the surface of water?
An iron needle floats on the surface of water due to surface tension; option [B]. Surface tension arises from the cohesive forces between water molecules, particularly at the water-air interface. This cohesion creates a thin film on the water's surface with higher tension than the bulk of the liquidRead more
An iron needle floats on the surface of water due to surface tension; option [B]. Surface tension arises from the cohesive forces between water molecules, particularly at the water-air interface. This cohesion creates a thin film on the water’s surface with higher tension than the bulk of the liquid. The surface tension acts like a “skin,” supporting lightweight objects such as the iron needle, allowing it to float. Unlike other materials, the iron needle’s density is higher than that of water, so it would typically sink. However, the strong surface tension of water counteracts the needle’s weight, effectively “holding it up” on the water’s surface. This phenomenon is observed in various contexts, from small insects walking on water to certain lightweight objects floating. Therefore, the correct option is [B] Due to surface tension, as it is the cohesive force at the water’s surface that enables the iron needle to float rather than sink.
See lessAbsorption of ink by blotting paper involves
Absorption of ink by blotting paper involves the capillary reaction phenomenon; option [B]. Capillary action occurs due to the cohesive and adhesive forces between the liquid molecules and the fibers of the paper. This interaction causes the ink to be drawn upward through the small pores in the papeRead more
Absorption of ink by blotting paper involves the capillary reaction phenomenon; option [B]. Capillary action occurs due to the cohesive and adhesive forces between the liquid molecules and the fibers of the paper. This interaction causes the ink to be drawn upward through the small pores in the paper, facilitating its absorption. Capillary action is crucial in processes like ink absorption in blotting paper, where it efficiently pulls the ink into the paper fibers. Viscosity of the ink refers to its resistance to flow and is not directly related to the adsorption process. Diffusion of ink through blotting involves the movement of ink molecules through the paper, which is not the primary mechanism in ink absorption by blotting paper. Siphon action requires a continuous flow of liquid, which is not applicable to the absorption of ink by blotting paper. Therefore, the correct option is [B] Capillary Reaction phenomenon.
See lessAction and reaction
Action and reaction have the same magnitude and opposite directions; option [D]. According to Newton's third law of motion, when one object exerts a force on another object (action), the second object exerts an equal but opposite force on the first object (reaction). These forces act on different obRead more
Action and reaction have the same magnitude and opposite directions; option [D]. According to Newton’s third law of motion, when one object exerts a force on another object (action), the second object exerts an equal but opposite force on the first object (reaction). These forces act on different objects, have equal magnitudes, and opposite directions. Therefore, all options are correct: [A] Work on two different objects, [B] Have the same magnitude, and [C] Have opposite directions. This fundamental principle of action and reaction is essential in understanding the dynamics of interactions between objects and is applicable in various fields of physics and engineering. It elucidates how forces are transmitted between objects and plays a critical role in analyzing and predicting the motion of systems governed by Newtonian mechanics.
See lessAt what angle should a ball be thrown from the horizontal so that it can cover the maximum horizontal distance?
To cover the maximum horizontal distance, a ball should be thrown at a 45° angle from the horizontal; option [D]. At this angle, the horizontal and vertical components of the initial velocity are equal, leading to the greatest range for a projectile launched with the same initial speed. Therefore, tRead more
To cover the maximum horizontal distance, a ball should be thrown at a 45° angle from the horizontal; option [D]. At this angle, the horizontal and vertical components of the initial velocity are equal, leading to the greatest range for a projectile launched with the same initial speed. Therefore, the correct option is [D] 45°. This principle is derived from the equations of projectile motion and is applicable in various contexts, from sports like basketball and javelin throwing to engineering applications such as projectile motion calculations. Understanding the optimal launch angle for maximum range is essential for achieving desired distances in projectile motion scenarios, making it a fundamental concept in physics and practical applications. Thus, launching the ball at a 45° angle ensures it travels the farthest horizontally compared to other angles listed.
See less