The most common way for a black hole to form is probably in a supernova, an exploding star. When a star with about 25 times the mass of the Sun ends its life, it explodes. The outer part of the star screams outward at high speed, but the inner part of the star, its core, collapses down. If there is enough mass, the gravity of the collapsing core will compress it so much that it can become a black hole. When it’s all over, the black hole will have a few times the mass of the Sun. This is called a “stellar-mass black hole”, what many astronomers think of as a “regular” black hole.
Motion is a relative concept . You are sitting on a train. A object on trains seems to be at rest from your perspective but it is in motion from the person standing on the ground.So it is tied to particular frame of refrence choosen by observer.
Now Different observer may use different frame of refrence , And velocity ,acceleration may be different from these different frame of reference
It is important to know how these measurement in different frame of refrence are related.
The acceleration vector has the same direction as instantanous change in velocity. Since the direction of the velocity changes in the direction in which the curve bends ,the acceleration is always pointing towards concavity of the curve
The acceleration in curvilinear motion can also be expressed in terms of two components
It only participates in EM interactions. Strong and weak interactions are not in photon domain of experience. When particle annihilate with anti particles the end product is often protons.Photon is its own anti particle.
We all know that Gauss’s law is basically the relation between the charge distribution producing the electrostatic field to the behaviour of electrostatic field in space. Also Gauss’s law is based on the fact that flux through any closed surface is a measure of total amount of charge inside that surface and any charge outside that surface would not contribute anything to the total flux.
Here in this post we will go through a quick recap of vector algebra keeping in mind that reader already had detail knowledge and problem solving skills related to the topic being discussed. Here we are briefing Vector Algebra because concepts of electrostatics , electromagnetism and many more physical phenomenon can best be conveniently expressed using this tool.
Electrostatics involves electric charges namely positive and negative charges, the forces between them which is known as electric force , the field that surrounds them, and their behavior in materials. Coulumb’s law is the simple relation that governs electrostatic interactions and the field around the charges is described using the concept of electric field. Coulumb’s law is a inverse square law which gives the force between two charges kept at some distance (say r ) apart from each other. Like Coulumb’s law, law of gravitation is also a inverse square law but gravitational interactions are only attractive in nature and electrical interactions are attractve as well as repulsive depending on the nature if interacting charges. Charges of same kind repel each other and charges different kinds , i.e. one charge positive and other negative , attract each other. One more thing electric interactions are much more stronger then gravitational interactions and gravitational force are almost negligible in comparison to the forces of electric origin.
CSIR-UGC National Eligibility Test (NET) for Junior Research Fellowship and Lecturer-ship Physical Science Syllabus
PART ‘A’ CORE
I. Mathematical Methods of Physics
Dimensional analysis. Vector algebra and vector calculus. Linear algebra, matrices, Cayley-Hamilton Theorem. Eigenvalues and eigenvectors. Linear ordinary differential equations of first & second order, Special functions (Hermite, Bessel, Laguerre and Legendre functions). Fourier series, Fourier and Laplace transforms.