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Have you ever wondered why celestial lightning falls and, then what causes it to fall? Why and how does such a loud sound come when lightning falls. So let’s start, When lightning occurs, the temperature of the surrounding air rises to about 28,000°C within an instant. This temperature is about five times higher than the … Read more
Constellation A group of stars appears to give the appearance of a particular shape when viewed from the earth. Our ancestors conceived some shapes in many names are known as a constellation. These constellations are named on the basis of their shape. For example- Ursa major Ursa Minor Orion Cygnus Hydra … 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
Black Hole The future of a neutron star depends on its mass. It is estimated that the contraction of heavy neutron stars can occur indefinitely. In the same order, when a neutron star of mass m shrinks to obtain radius r=2Gm/c²,it becomes a black hole. Michel first envisaged the existence of a black hole. … Read more
Octopus blood Let us talk today about why the color of octopus’s blood is blue and what is the reason for it. After all, what is there in his blood due to which the color of his blood is blue? Apart from humans, there are many creatures whose blood is red in … Read more
Physical World The correct concept of force is given by Newton’s laws of motion. We experience many forces in the micro world as well as in the macro world. Gravitational force and electromagnetic force are experienced in the physical world. Because the range of both of them is infinite. Whereas in the microscopic world, nuclear … Read more
