W. H. Miller in 1839 represented the planes of a crystal by a set of three integers h, k and l, called the Miller indices. To obtained the Miller indices for any crystal plane, the ratios of the intercepts made by the unit plane to those made by the given plane or its parallel plane […]
Theoretical Density :- Knowing the unit cell dimensions, the theoretical density d of a cubic crystal can be calculated from the equation d = Z M / N V where Z is the number of atoms in the unit cell, M is the molar mass, V is the volume of the unit cell and N
Calculation involving Unit Cell dimensions : Theoretical Density Read Post »
Crystal Lattice :- If the three dimensional arrangement of constituent particles like atoms, molecules or ions in a crystal is represented diagrammatically, in which each particle is depicted as a point, the arrangement is called crystal lattice. In 1848, Auguste Bravais showed with the help of geometrical calculations that there are 14 possible three dimensional
Solid state :- Types of Solid :- On the basis of the nature of order present in the arrangement of their constituent particles, Solid or solid state can be classified as Crystalline and Amorphous. Crystalline Solid :- A crystalline solid state usually consists of a large number of small crystals, each of them having a
Solid state, Types of Solid and their characteristics Read Post »
Dispersion of light :- Dispersion of light is the phenomenon of splitting of a beam of white light into its 7 constituent colours when passed through a transparent medium like water droplets or Prism . It was discovered by Isaac Newton in 1666 . Newton discovered that light is made up of seven different colours
Dispersion by a prism :- When white light ( Sun light ) is incident on a glass prism, the emergent light is seen to be consisting of several colours, the phenomenon of splitting of light into several component colours is known as dispersion. The different component colours that appear in sequence are violet, indigo, blue,
Angle of deviation ( δ ) :- The passes of light through a triangular prism ABC, The angles of incidence and refraction at the first face AB are i₁ and r₁ while the angle of incidence at the second face AC is r₂ and the angle of refraction or emergence i₂ . The angle between
Angle of Deviation , Refractive index of the Prism Read Post »
Equivalent focal length of two lenses :- Let us consider two lenses L₁ ( focal length f₁ ) and L₂ ( focal length f₂ ) are separated by a distance d and P₂ is equivalent lens of both lenses ( focal length f ). Angle of deviation produce by the lenses P, L₁ and L₂
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Let us consider two lenses A anb B of focal length f₁ and f₂ placed in contact with each other. Let the object be placed at a point O beyond the focus of the first lens A. The first lens produces an image at I₁ is real, it serves as a virtual object for the
Refraction of light at a convex surface :- 1. For real image :- The figure shows the geometry of formation of image I of an object O on the principal axis of a spherical surface ( convex ) with centre of curvature C and radius of curvature R. The rays are incident from a medium
1. Incomplete dominance :- It is a post Mendelian discovery. In the case heterozygous condition of gene results in intermediate phenotype as one allele is only incompletely don’t over the other. The intermediate of flower colour in the Mirabilis jalapa is a good example to understand incomplete dominance. In a cross between true breeding red
Exceptions to Mendel’s laws : Incomplete dominance, Co-dominance and Linkage Read Post »
Mendel’s laws of inheritance :- Mendel’s present his paper on principles of heredity at the annual conventy on natural history society at Brun ( Austria ) in 1895. This paper use published in the proceeding on the conference in 1866. Tittle of this paper was experiment in plant hybridization. These principles are – 1. Law
Mendel’s laws of inheritance and Chromosomal theory of inheritance Read Post »
