What is meant by fine structure?
Fine structure, in spectroscopy, the splitting of the main spectral lines of an atom into two or more components, each representing a slightly different wavelength. Fine structure is produced when an atom emits light in making the transition from one energy state to another.
What is J in spectroscopy?
The quantum number J refers to the total angular momentum, as before. Since there are three independent moments of inertia, there are two other independent quantum numbers to consider, but the term values for an asymmetric rotor cannot be derived in closed form.
What is meant by selection rule?
In physics and chemistry, a selection rule, or transition rule, formally constrains the possible transitions of a system from one quantum state to another. Selection rules have been derived for electromagnetic transitions in molecules, in atoms, in atomic nuclei, and so on.
What do you mean by rigid rotator?
The rigid rotor is a mechanical model of rotating systems. An arbitrary rigid rotor is a 3-dimensional rigid object, such as a top. To orient such an object in space requires three angles, known as Euler angles.
What is the meaning of moment of inertia?
Moment of inertia, in physics, quantitative measure of the rotational inertia of a body—i.e., the opposition that the body exhibits to having its speed of rotation about an axis altered by the application of a torque (turning force).
What is a rigid molecule?
As was stated before, a rigid molecule is not one for which all the nuclei it contains are rigidly bound to each other, or for which the distance between the atoms cannot change. On the other hand, non-rigid molecules are different in that they can tunnel through a potential barrier from one configuration to another.
What is meant by rotor?
The rotor is a moving component of an electromagnetic system in the electric motor, electric generator, or alternator. Its rotation is due to the interaction between the windings and magnetic fields which produces a torque around the rotor’s axis.
What are the different types of rotors?
Three types of centrifuge rotor. Centrifuge rotors fall into three categories: swinging-bucket rotors, fixed-angle rotors, and vertical rotors. Each category is designed to address three key factors: 1) type of centrifugation (differential, rate-zonal, or isopycnic), 2) speed, and 3) volume range.
What is rotor speed?
Rotor spinning Rotor speed depends, in part, on rotor diameter. Rotor speeds typically lie in the 120–210 m/s range, but mostly between 150 and 190 m/s, with a tendency to be higher with a smaller rotor diameter [6].
What does a rotor do in a generator?
Rotating Armature Generator In the rotating armature AC generator as illustrated in Figure 1, the stator provides a stationary electromagnetic field. The rotor, acting as the armature, rotates in the field, cutting the lines of force and producing the desired output voltage.
What does a stator do in a generator?
In an electric motor, the stator provides a rotating magnetic field that drives the rotating armature; in a generator, the stator converts the rotating magnetic field to electric current. In fluid powered devices, the stator guides the flow of fluid to or from the rotating part of the system.
What is a rectifier on a generator?
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. Rectification may serve in roles other than to generate direct current for use as a source of power.
What is a rotor on a helicopter?
The rotor system is the rotating part of a helicopter which generates lift. The rotor consists of a mast, hub, and rotor blades. The mast is a hollow cylindrical metal shaft which extends upwards from and is driven and sometimes supported by the transmission.
Do helicopters have a clutch?
On reciprocating helicopters, the two main types of clutches are the centrifugal clutch and the belt drive clutch. The centrifugal clutch is made up of an inner assembly and an outer drum.
How do dual rotor helicopters work?
Tandem rotor helicopters, however, use counter-rotating rotors, with each cancelling out the other’s torque. To achieve pitch, opposite collective is applied to each rotor; decreasing the lift produced at one end, while increasing lift at the opposite end, effectively tilting the helicopter forward or back.
How fast do helicopters fly?
An average helicopter can reach a top speed of somewhere between 130 and 140 knots, which comes out to about 160 mph. The Eurocopter X3 can reach a top speed somewhere in the neighborhood of 267 mph (430 km/hr or 232 kts) in stable and level flight.
Why was Kobe in a helicopter?
The National Transportation Safety Board primarily blamed pilot Ara Zobayan in the Jan. 26, 2020 crash that killed him along with Bryant, the basketball star’s daughter and six other passengers heading to a girls basketball tournament.
Can helicopters break the sound barrier?
Helicopter blades do not break the sound barrier. When they approach the speed of sound the opposite side blade is moving at its slowest speed and a dangerous condition called “retreating blade stall” occurs which causes the helicopter to roll towards the retreating blade side and nose down.
Do helicopters have speed limits?
These (and other) problems limit the practical speed of a conventional helicopter to around 160–200 knots (300–370 km/h).
What is the quietest helicopter in the world?
As the quietest helicopter on the market in its category, the H130’s Fenestron® shrouded tail rotor and automatic variable rotor speed control contribute to its significantly reduced external sound level.