Millikan's Oil-drop Experiment

-

            Millikan's Oil-drop Experiment

In 1909, Robert Millikan was the first to find the charge of an electron his now-famous oil-drop experiment. In that experiment, tiny oil drops were sprayed into a uniform electric field between a horizontal pair of oppositely charged plates. The drops were observed with a magnifying eyepiece, and the electric field was adjusted so that the upward force on some negatively charged oil drops was just sufficient to balance the downward force of gravity. That is, when suspended, upward force qe just equaled Mg. Millikan accurately measured the charges on many oil drops and found the values to be whole number multiples of 1.6 x 10-19 C the charge of the electron. For this, he won the Nobel prize.

Comments

Post a Comment

Popular posts from this blog

Distinction between Electromagnetic Waves and Matter Waves

-
Image
  Difference   between Electromagnetic Waves and Matter Waves » Electromagnetic waves 1. Electromagnetic waves are associated with electric and magnetic fields perpendicular to each other and to the direction of propagation of radiation. 2. Electromagnetic waves can be radiated into space or emitted. 3. They do not require any medium for propagation i.e., these waves can pass through vacuum. 4. All electromagnetic waves travel with the same velocity.  5. The velocity of all electromagnetic waves is equal to that of light (3 x 108 m/s). 6. The wavelengths of electromagnetic radiation are much large .   » Matter waves 1. Matter waves may not be associated with electric and magnetic fields. 2. Matter waves are neither radiated into space nor emitted by the particles. These are simply associated with the particles 3. They require medium for propagation i.e., these waves cannot pass through vacuum. 4. Matter waves travel with different vel...
Read more

QUANTUM NUMBERS (Principal, Azimuthal, Magnetic and Spin)

-
Image
                  QUANTUM NUMBERS  Orbitals represent regions in the space around the nucleus where the probability of finding the electron is maximum. A large number of electron orbitals are possible in atom. These can be distinguished by their size, shape and orientation of the orbitals. To describe each electron in an atom in different orbitals, we need a set of three numbers known as quantum numbers. These are designated as n, l and m. In addition to these three numbers another quantum number is also needed which specifies the spin of the electron. These four numbers are called quantum numbers. These are discussed below: 1. Principal quantum number (n) :  This quantum number determines the main energy shell or level in which the electron is present. It is denoted by n. It can have whole number values starting from 1 such as n = 1, 2, 3, 4 ... This quantum number also identifies as shell. The shell with n 1 is called the first sh...
Read more

Diagonal Relationship between Beryllium and Aluminium || Relation between Beryllium and Aluminium

-
  Diagonal Relationship between Beryllium and Aluminium The ionic radius of Beryllium (Be 2+) is estimated to be nearly 31 pm; the charge/radius ratio Or e/m ratio is nearly the same as that of the Al 3+ ion. Hence beryllium resembles aluminium in these ways. Some of the similarities are given below: » Like Aluminium, Beryllium(be) is not readily attacked by acids H+ donor because of the formation of an oxide film on the surface of the metal by reacting with oxygen, i.e. they are rendered passive by nitric acid. » Beryllium hydroxide[[Be(OH)4]2] dissolves in excess of alkali to give a beryllate ion, [ Be(OH)4]2– just as aluminium hydroxide[Al(OH)3] gives aluminate ion, [Al(OH)4] » The chlorides of metals beryllium and aluminium have Cl– bridged chloride structure in vapour phase. Both the chlorides are soluble in organic solvents and are strong as Lewis acids They are used as Friedel Craft catalysts. » Beryllium(Be) and aluminium(Al) ions have strong tendency to form complexes, (Be...
Read more

Changing Trends And Career in Physical Education Solutions || Objective Type Questions || Objective Answers Chapter 1 Class 11 Solution || Physical Education ||

-
Ques 1: “Physical Eduction is the sum of changes in an individual caused by experience centring motor activity” Who said this? (a) Prince martin  (b) Millions (c) Charls A.Butchar  (d) Cassidy Ans :  (d) Cassidy Ques 2: “Physical Education is the sum of men’s physical activities selected as to kind and conducted as to outcomes” who said this? (a) C.C.Covel  (b) Charls A Butcha (c) Williams  (d) J.B. Nash Ans :  (c) Williams Ques 3 : How many objectives of physical Education are there? (a) Four  (b) Five (c) Three  (d) Six Ans : (b) Five Ques 4 : What is the aim of physical Education? (a) Physical development  (b) Motor development (c) Mental Development  (d) All Round development Ans : (d) All Round development Ques 5: Sports management is based upon....? (a) Efficient and Talented officials  (b) Smart and clever officials (c) Weak and Greedy officials  (d) None of these  Ans : (a) Efficient and Talented of...
Read more

Math question

-
Image
A tower, x metre, has a flagstaff at its top. The tower and flagstaff subtends equal angles at a point distant y metre from the foot of the tower. Then find the length of the flagstaff ( in metre). 
Read more