Physics miscellaneous
- The water from a hand pump is warm in winter because
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In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
Correct Option: B
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
- If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is
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The pressure exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration of gravity. Static fluid pressure does not depend on the shape, total mass, or surface area of the liquid.
Correct Option: B
The pressure exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration of gravity. Static fluid pressure does not depend on the shape, total mass, or surface area of the liquid.
- The Newton’s First Law is also called as
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According to Newton’s first law, an object that is at rest will stay at rest unless an unbalanced force acts upon it and an object that is in motion will not change its velocity unless an unbalanced force acts upon it. So this law is known as the law of inertia.
Correct Option: B
According to Newton’s first law, an object that is at rest will stay at rest unless an unbalanced force acts upon it and an object that is in motion will not change its velocity unless an unbalanced force acts upon it. So this law is known as the law of inertia.
- Hydraulic machines work under the Principle of :
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Hydraulic Machinery refer to machines and equipment which use high pressure fluid to accomplish any work in industrial fields. These machines work on the basis of Pascal’s Law which says “The pressure, in a static hydraulic fluid in a closed system is everywhere the same”.
Correct Option: C
Hydraulic Machinery refer to machines and equipment which use high pressure fluid to accomplish any work in industrial fields. These machines work on the basis of Pascal’s Law which says “The pressure, in a static hydraulic fluid in a closed system is everywhere the same”.
- A black body can absorb radiations of ;
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A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
Correct Option: D
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.