Physics Education

Elastic limit  - The maximum stress which can be applied on a body without permanent deformation is called elastic limit. Hook's law - Within the elastic limit stress developed in a body is directly proportional to strain produced in it. Elastic constants & their relation Corresponding to three different types of stress & strain; there are three different modulus of elasticity. (i)  Young's Modulus (Y)  (ii)  Bulk Modulus (K) (iii)  Modulus of rigidity (η)  Young's Modulus (Y) Within the elastic limits, ratio of longitudinal stress to  longitudinal strain is called as  Young's Modulus denoted by "Y". Bulk Modulus (K) Within the elastic limits, ratio of volume stress to  volume  strain is called as  Bulk Modulus denoted by "K". Negative sign indicates that when pressure   increase volume decrease and vice versa. Compressibility Reciprocal of bulk modulus of elasticity is know...

Young's double slit experiment Young's in 1801 demonstrated the phenomenon of interference of light by a simple experiment. S is a narrow slit (of width 1 about 1 mm) lighted by a monochromatic (same color and wave length) source of light of at a suitable distance (about 10 cm)  from s, there are two fine slits S 1  & S 2  about 0.5 mm, parallel to S. when a screen is placed at a distance (about 2m) from the slits S 1  & S 2 ; alternate bright & dark fringes appear on the screen. The fringes disappear when one of the slits S 1  & S 2  is covered. click here to know basic of interference Explanation - Young's experiment can be explained on the basis of interference of light. According to Huygens principle, source of light "S" sends out spherical wave fronts. Let the solid arcs represent the crest & dotted arcs represent the troughs. These wave fronts reach the S 1  & S 2  click here to know about wavefron t ...

Spherometer A spherometer is an instrument for the precise measurement of the radius of curvature of a spherical surface. It consist of a base circle of three outer legs; & a center leg, which can be raised or lowered. Pitch - It is the distance between two consecutive threads of a screw or It is the distance moved in one rotation by screw. zero Error - When the central leg touches the same surface as the other three legs are; & if zero of the circular scale does not coincide with the  zero of the  main scale then the instrument have zero error. It is of two types- (i)   Positive zero error= “0” of the circular scale lies below the "0” of the main scale. (ii)   Negative zero error= “0” of the circular scale lies above the "0” of the main scale. Total Reading(R)     Where L = the distance between the any two legs. h = height of curve surface from center leg. Formula for h = M.S.R + C.S.R x L.C C...