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Showing posts from January, 2017

FOCAL POINT - FOCAL LENGTH - REFRACTING POWER

Focal point: (Focus point)                When light rays incident on a lens parallel to the principle axis of a lens, focus at a point. the point is called focus point or focal point.       Focal length :   Distance between focal point and optical center of a lens is called focal length.         Optical power:(Refracting power)       Reciprocal of the focal length is called optical power. SI units are diopter or 1/meter.

INTERFERENCE

Interference:               When two light waves superimpose then alternative bright and dark fringes are formed in the region of superimposing.                                                or                     The modification of intensity in the region of superimpose. Types of interference:            Interference of two types. Those are    1. Constructive interference.   2. Destructive interference.

AN IDEA TO SAVE ELECTRICITY

AN IDEA TO SAVE ELECTRICITY GLOW THE LAMP WITHOUT ELECTRICITY Ò  In this presentation we used a simple idea to save the electricity consumed by bed lamps. Ò  We can convert mechanical energy to electrical energy which is in regard to the law on conservation of energy. Ò  The apparatus used is electric motor, plastic fan wings, connecting wires, and LED.    The process of conversion of mechanical energy to electrical energy, you can see in the following video.

PHYSICS PRACTICAL PROCEDURE

Physics practical procedure for class 12 students to do the practical. LINEAR RESISTANCE OF A GIVEN WIRE  AIM :  To determine resistance per cm i.e linear resistance of a given wire by plotting a graph of potential difference versus current. APPARATUS:   A resistance wire, a voltmeter, an ammeter, a battery, a rheostat, a meter scale, a one-way key, and connecting wire. FORMULA:              The resistance of given wire   R = V/i   ohm             Where V – Voltage applied in volt  and i – Current through the wire in ampere       Linear resistance of given wire     σ = R/l GRAPH: Ohm's law graph TABULAR FORM FOR UNKNOWN RESISTANCE: S.No The voltage across the wire            V in volt Current through the wire               I   in amp Resistance        R = V/I     in ohm   1   2   3   4   5   6 RESULT: The graph between V and i is a strai