1. Axial or Longitudinal Position Suppose an electric dipole with dipole moment P. We want to calculate the electric field intensity at a point P located at a distance r from the centre o of the dipole. Electric field intensity at point P due to +q charge E₁ = [1/4π€0].q/(r+l)²] Similarly, Electric field intensity at … Read more
Electric force line Electric force lines are imaginary but the electric fields generated by them are real. A tangent drawn at any point to the electric field line represents intensity of the electric field at that point. Properties of electric line of force 1. These lines run from positive charge and end at negative charge. … Read more
Importance of Coulomb’s law When a charge is stationary then only the electric force acts on it. Which was discovered by Coulomb. Therefore it is also called Coulomb force.When a charge is stationary then only the electric force acts on it. Which was discovered by Coulomb. Therefore it is also called Coulomb force. Coulomb’s law … Read more
Electric charge Electricity is the factor by which charge is generated in any object or substance. When a substance becomes electrostatic, the substance acquires charge. Therefore such a substance is called a charged substance. There are two types of electric charges. Those substances which accept charge have an excess of charge and those substances which … Read more
Photocell The photocell (light cell) is a craft technological application of the photoelectric effect. The photocell is a device that converts light energy into electrical energy. It is sometimes called the electric eye. A photocell consists of a semi-cylindrical light-sensitive metal plate C (emitter) and a wire loop (loop) A (collector) mounted in a vacuum … Read more
Error Analysis, Percentage Error *Numerical questions* 1. The width of a road of 20 meters is measured with the help of a 1 meter long rod. What is the maximum percentage error that can occur from this measurement? Solution- x=20 m ∆x=1 m percent error, =(∆x/x)×100 =(1/20)×100 =5% 2. The length of a … Read more
Dimensions Of Physical Quantities The dimensions of any physical quantity are those powers which are raised to the basic units to express the unit of that quantity. To write the dimensions of physical quantities in mechanical and thermodynamics, the basic units for length, time, mass, and temperature are represented by L, T, M, and θ … Read more
Physical quantities All the quantities which are related to any physical phenomena and can be represented by a number and can be measured directly and indirectly are called physical quantities. Example– Length, mass, temperature, speed, force, time etc. There are two types of physical quantities 1. Basic quantities Those physical quantities which … Read more
Significant figures All the reliable and one doubtful figures included in a measurement are called significant figures. Some rules for calculating significant figures 1. All non-zero numbers are significant. Example– 1,2,3,5,9 have 5 significant digits. 2. Zero between two non-zero numbers is significant. Example– 12567.09 has 7 significant figures. 3. A … Read more
Huygen’s Principle When we throw a small stone in a calm water pond, waves propagate around the rebound point. Every point on the surface starts oscillating with time. The photograph of the page at any given moment will show the circular rings above which the disturbance is maximum. Apparently, all the points in this type … Read more
