General Physics

Water expands on freezing. When liquid water is cooled, it contracts like one would expect until a temperature of approximately 4 degrees Celsius is reached. After that, it expands slightly until it reaches the freezing point, and then when it freezes it expands by approximately 9%. The fact that water expands upon freezing causes icebergs to float.

A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance.

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In electronics and electrical engineering, a fuse is a type of low resistance resistor that acts as a sacrificial device to provide over-current protection, of either the load or source circuit.

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A dynamo is an electrical generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter.

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A telescope assists the eye chiefly in two way by enlarging the visual angle under which a distant object is seen, and thus magnifying that object; and, secondly, by collecting, and conveying to the eye, a larger beam of light than would enter the naked organ, thus rendering objects distinct and visible which would otherwise be indistinct and or invisible.

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Both stones at the same time. The initial speed is 0 for both stones, and the only acceleration working in that system would be g (Gravity acceleration). So, as the distance is the same, the final speed will be the same time. The only reason which could change this result is a difference in the shape of the stones

On average, seawater in the world’s oceans has a salinity of about 3.5% (35 g/L, or 599 mM). Seawater is denser than both fresh water and pure water (density 1.0 g/ml ) because the dissolved salts add mass without contributing significantly to the volume.

Galileo’s experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. In general, it’s main function is to convert kinetic friction into rolling friction.

The poles remains same whether the magnet is cut into two equal half or more and also pole strength remains same but magnetic moment reduces due to decrease in the length of the magnet. If a bar magnet is suspended by a thread, it will come to rest in a position close to the north-south direction. The end of the magnetic toward the north is called north pole (N-pole) of the magnet and the other end the south pole (S-pole).

The ozone layer is a layer in Earth’s atmosphere containing relatively high concentrations of ozone (O3). The ozone layer absorbs 97–99% of the Sun’s mediumfrequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth