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ELECTRICAL MEASURING INSTRUMENTS For the detection or measurement of electric current, potential difference, and resistance certain instruments have been devised viz. The galvanometer for the detection of small currents measurements of small currents of the order of micro amperes or mili amperes the voltmeter or potentiometer for the measurement of potential difference (and voltage) between two points of a circuit are the EMF of a source the ammeter for the measurement of large currents the wheatstone bridge the meter Bridge the post office box and the ohmmeter for the measurement of resistance. THE MOVING COIL GALVANOMETER The moving coil galvanometer is a basic electrical instrument it is used for the detection (and Measurement) of small currents. Its underlying principle is the fact that when a current flows in a rectangular coil placed in a magnetic field it experiences a magnetic torque. If it is free to rotate under a controlling torque, it rotates through an angle proportional t...
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ISOTOPES OF HYDROGEN

The existence of hydrogen of elements was first discovered by J.J. Thomson in 1912-1913 while working on the properties of neon.The isotopes may be defined as 

"Atoms of the same elements having same atomic number but different mass numbers"

It may also be defined as

"Atoms that have the same number of protons but different number of neutrons in their respective nuclei"

Nearly all elements found in nature are mixture of several isotopes.Isotopes of hydrogen are given special names while isotopes of other elements are not given any special name.

There are 3 isotopes of hydrogen, mainly:

  1. Protium
  2. Deuterium
  3. Tritium

(i) Protium 

It is also known as ordinary Hydrogen.It contains one proton in the nucleus and there is one electron in 1s orbital (First Shell). It has atomic number one and atomic mass number is also 1 . Naturally free occuring hydrogen or in the form of compounds contain about 99.98% protium.

(ii)Deuterium 

It is also called heavy hydrogen although this name is inappropriate because there is another isotope of hydrogen namely "Tritium" which is even heavier than deuterium.

It contains one proton and one neutron in the nucleus and one electron in 1s orbital.It has atomic number 1 and atomic mass number 2. It is present in naturally occurring hydrogen to the extent of about 0.0156% i.e in the ratio 1:15000

(iii) Tritium

It contains 1 proton and 2 neutrons in the nucleus and 1 electron in 1s orbital.It has atomic number 1 and atomic mass number 3. It occurs in very small quantities in the naturally occurring hydrogen to the extent of about 4x10 exponent -15 %. It is radio active form of hydrogen and has half life of 12.5years.

Hope you will understand after reading this article,

What are isotopes ?
What are isotopes of hydrogen ?
Which property of isotopes of hydrogen will be similar ?
Which isotope of hydrogen is radioactive ?
How many types of Isotopes ?
Uses of isotopes.

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