Param Himalaya - परम हिमालय

Chapter- 9 Light Reflection and Refraction Chapter- 9 Light Reflection and Refraction is prepared by senior and renown teachers of Param Himalaya primary focus while solving science questions of class-10 is NCERT textbook, Read the theory of this chapter and try to understand the meaning. 1. Define the principle focus of a concave mirror. Solution : Principal focus of a concave mirror is the point on its principal axis, where light rays coming parallel to principal axis actually converge after reflection from mirror. 2. The radius of curvature of a spherical mirror is 20 cm. what is its focal length? Solution : Focal length (f)= R/2 = 20 cm/2 = 10 cm. 3. Name a mirror that can give an erect and enlarged image of an object. Solution : Only a concave mirror can give a erect and enlarged image of an object. 4. Why do we prefer a convex mirror as a rear-view mirror in vehicles? Solution : We prefer a convex mirror as a rear-view mirror in vehicles because a convex mirror gives an erect and...

Difference between Distance and Displacement :  S.No Distance Displacement  1 Distance is the length of the actual path travelled by an object in a given interval of time Displacement is the shortest distance between the initial and final position of a moving object in a particular direction 2 Distance travel by an object depends upon the shape of the path followed by the object in going from initial position to the final position. The displacement of an object between initial and final position of the object does not depend upon shape of the path followed by it 3 Distance travelled buy an object in a given interval of time is always positive Displacement of an object in a given interval of time maybe positive, negative or zero. 4 Distance is a scalar quantity Displacement is a vector quantity

Definition of Distance :  The actual path or length travelled by a object during its journey from its initial position to its final position is called the distance. Distance is a scalar quantity which requires only magnitude but no direction to explain it. Example : Ram travelled 65 km. (Distance is measured by odometer in vehicles.) Definition of Displacement :  The shortest distance between the initial position and the final position of a moving object in the given interval of a time. Displacement = Finial Position - Initial Position  Displacement is a vector quantity requiring both magnitude and direction for its explanation. Example, Ramesh travelled 65 km south-west from Clock Tower. Displacement can be zero (when initial point and final point of motion are same) Example, circular motion.

Method of charging a conductor and induction - Param Himalaya  A material can be electrified or electrically charged if some charge is given to the material or taken out of the material. Ordinarily a body is said to be electrified or electrically charged if it has excess electrons or it is deficit of electrons. In fact , every neutral objects consists of positive and negative charges which are equal and opposite in polarity , so net charge on the neutral objects is zero.  Net Static charge can exist on an object in the following ways :  1. Charging by physical contact / Electrification by conduction :  if an uncharge conductor is touched with a charge conductor,  the uncharge conductor may acquire charge similar to the charge conductor. It happens because some of the charges are shared at the point of contact of the conductors. 2. Charging by friction / Frictional Electrification :  The electrostatic charges ( i.e , charges at rest ) developed on insulating...

What is conductors and Insulators with Definition and Examples ? - Param Himalaya Material can be divided according to the flow of electric charges in two main classes :  1. Conductors : The material which allow flow of electric charges through them easily are called conductors. These electrons are free to move about in the whole conductor and can be transferred easily our of the conductor by supplying a small amount of energy and hence they are known as mobile charges. Example : Silver , copper , Aluminum , iron , mercury , the earth , Human being , Solution of salt. 2. Insulator : The material which donot allow the flow of electric charges through them are called insulator. They have negligible small number of free electron or no free electrons. The electric charge given to the insulator , by rubbing of insulator can cause transfer of a few electrons. If glass rod is rubbed with silk or rubber rod with wool. They get charged but these charges remain Statics. Example : Glass rub...

What is Electric charge and It type unit and Dimensions  Definition of Electric charge Dimention and it's S.I Unit :  Electric Charge is the inherent property associated with matter due to which it produce and experience electrical and magnetic effect . S.I unit of charge : Coulomb Largest Unit of charge : Faraday  1 Faraday = 96500 Columbs  Smallest Unit of charge : Franklin Electrostatic unit (ESU) = Franklin 1esu = 1 Franklin = 3.335 × 10 ^ -10 C Or 1 C = 3×10^9 esu 1 emu = 10 C = 3 × 10^10 esu  Dimensions formula : [AT] Experiment and analysis : Type of electric charges  1. If two glass rod rubbed with wool or silk cloth are brought close to each other , they repel each other. 2. Two strands of wool or two pieces of slik cloth with which the rods were rubbed , also repel each other's but glass rod and wool attracted other. 3. Two plastic rods rubbed with cat's Fur repelled each rod and attracted the glass rod and repel the silk or wool with which the gl...

Class 12 Physics - What is Electrostatic and it's Application  1.1 Introduction : Electric charge / Electrostatic  1. The experience of seeing a spark or hearing a crackle when we took off our synthetic clothes or sweater particularly in dry weather. 2. The lightening that we see in the sky during thunderstorm. 3. Sensation of an electric shock either while opening the door of a car or holding the iron bar of a bus after sliding from our seat.  Electricity :  The name electricity is coined from the Greek word elektron meaning amber. Many such pairs of materials were known which on rubbing could attract light object like straw , pith balls and bits of papers. The amber getting the property of attracting bits of paper and dust particles. This property of attraction is said "Electrified". Electrification is defined as the transfer of electrons from one body to another when they are rubbed with each other. Electrostatic :  The branch of Physics which deal with the s...