Physics

1.

Types of Radioactive Decay

Radioactive decay is the process by which an unstable nucleus loses energy by emitting radiation. The three main types of radioactive decay are:

Bohr’s Atomic Model

1. Proposed by Niels Bohr in 1913 to address the limitations of Rutherford’s atomic model.
2. Electrons move in specific quantized orbits around the nucleus without radiating energy.
3. These orbits are called energy levels or shells, denoted by n (n = 1, 2, 3...).
4. The energy of an electron is constant in a specific orbit.
5. An electron can move to a higher orbit by absorbing energy or to a lower orbit by emitting energy

1. An atom is the smallest unit of matter that retains the properties of an element.
2. It consists of a nucleus at the center and electrons orbiting around it.
3. The nucleus contains protons (positively charged particles) and neutrons (neutral particles).
4. Electrons are negatively charged and occupy distinct energy levels or shells.
5. Atoms are electrically neutral because the number of protons equals the number of electrons.

Discover

1. A transformer is an electrical device used to change the voltage levels in an AC circuit.
2. It operates on the principle of electromagnetic induction and mutual induction between two coils.

Working Principle of a Transformer

• Based on Faraday's laws of electromagnetic induction, a varying current in the primary coil produces a varying magnetic flux.
• This magnetic flux links to the secondary coil through a common core, inducing an EMF in the secondary coil.
• The transformer w

1. Lenz's Law explains the direction of the induced EMF and current in electromagnetic induction.
2. It is an extension of Faraday's laws of electromagnetic induction, focusing on the conservation of energy.

Lenz’s Law

• Statement: The direction of the induced current is such that it opposes the change in magnetic flux that caused it.
• Mathematically represented as: EMF = -dΦ/dt, where the negative sign signifies opposition to change (as per Lenz’s Law).
• Ensures compliance with t

1. Electromagnetic induction is the process of generating an electromotive force (EMF) by changing the magnetic field around a conductor.
2. Discovered by Michael Faraday in 1831, this phenomenon is the foundation of modern electrical technology.

Faraday's Laws of Electromagnetic Induction

First Law

• Faraday's First Law: An EMF is induced in a conductor whenever there is a change in the magnetic flux linked with it.
• The change in magnetic flux can be caused by moving the conductor, changing the

Basics of Electromagnets

1. An electromagnet is a type of magnet created by passing an electric current through a coil of wire.
2. The magnetic field is produced by the electric current, and it disappears when the current is stopped.
3. The strength of an electromagnet depends on the number of turns in the coil, the current passing through it, and the presence of a ferromagnetic core.
4. Electromagnets are temporary magnets, unlike permanent magnets.
5. The dir

Earth's Magnetism

1. Earth behaves like a giant magnet with a magnetic field generated by the movement of molten iron and nickel in its outer core.
2. The Earth's magnetic field protects us from solar wind and harmful cosmic radiation.
3. The magnetic field is strongest near the magnetic poles and weakest near the equator.
4. The geomagnetic field resembles that of a dipole tilted by about 11 degrees from the Earth's rotational axis.
5. Magnetic field lines eme

Magnets

1. A magnet is an object that generates a magnetic field and can attract ferromagnetic materials like iron, nickel, and cobalt.
2. Natural magnets are naturally occurring substances like magnetite, while artificial magnets are man-made.
3. Magnets have two poles, north and south, where the magnetic force is strongest.
4. Like poles repel each other, and unlike poles attract each other.
5. Magnets can lose their magnetism through