Engineering

In 1960, Maiman constructed the Ruby laser. It is a three-level solid-state laser and is emitting red light of wavelength 694.3 nm.

Rate of Stimulated emission depends upon the number of atoms present in the excited state as well as the energy density of photons.

The number of atoms present in the excited state is greater than the number of atoms in the ground state is called population inversion.

Simple Harmonic Motion (SHM) is when the restoring force is directly proportional to the displacement of the body from its mean position.

Magnetic Hysteresis Curve represents the relation between magnetizing force (H) and magnetic flux intensity for ferromagnetic material.

The multiplexer is a special type of combinational circuit which has n-data inputs, one output and m inputs select lines with 2^m = n.

The IC 555 timer is an 8 pin chip. It is used in applications such as multivibratiors. It operates in astable, bistable and monostable mode.

The losses in transformer are listed below. Some of them occur due to alternating flux or due to ohmic resistance in the windings.

The Programmable Interrupt controller is also known as PIC micro-controller. It is used as interfacing device. It has different operating modes.