Miscellaneous Physics Part-2

Isohaline is a line drawn on a map or chart to indicate connecting points of equal salinity in the ocean.

Isobar is a line connecting points of equal atmospheric pressure.

Isoheight is a line of constant height above a certain reference point.

Isobath line connects points of equal underwater depth.

Ecocline: This term is more broadly ecological. It refers to a transition zone between two different ecosystems or communities.

Paramagnetism arises due to the presence of unpaired electrons in an atom or molecule. These unpaired electrons have their own magnetic moment, and when an external magnetic field is applied, these moments align themselves in the direction of the field, resulting in a weak attraction to the magnet.

Iron (Fe), Nickel (Ni), and Cobalt (Co) are ferromagnetic metals. This means they have a strong attraction to magnets and can even become magnetized themselves.

Aluminium (Al) is a paramagnetic metal. Paramagnetic materials are weakly attracted to magnets, but the attraction is usually not strong enough to be noticeable in everyday situations with common household magnets

Earth as a Giant Magnet: The Earth behaves like a giant bar magnet. It has a magnetic field with a north and a south magnetic pole.

The Compass Needle: A compass needle is a small, lightweight magnet that is free to rotate on a pivot. It has its own north-seeking pole and south-seeking pole.

 "North-Seeking" Needle Points North: Because opposite poles attract, the "north-seeking" pole of the compass needle (which we often just call the "north" end) is attracted to the Earth's magnetic south pole, which is in the general direction of the geographic North Pole.

The tape of a tape recorder consists of a plastic backing coated with a thin layer of tiny particles of ferromagnetic powder.

Ferromagnetic materials can be easily magnetized and retain their magnetism. This property is crucial for recording and storing magnetic signals. When the recording head of the tape recorder passes over the tape, it creates a varying magnetic field that aligns the magnetic domains in the ferromagnetic coating according to the audio signal.

A Joint Physics Institute of the National Institute of Standards and Technology (NIST), and the University of Colorado of USA. Recently, JILA has also developed a new atomic clock that will not lose or gain a second in 15 billion years. The scientists claim that it is the most accurate clock ever built.