# Mu

**mu**- A letter of the Greek alphabet.
**MU**- Symbol for Amplification Factor.
**Mud Drum**- A water drum, particularly one mounted low on the boiler whose function is primarily to trap mud from circulation.
**Muddy**- A listening term, a sound that is poorly defined, sloppy or vague. For example, a "muddy" bass is often boomy with all the notes tending to run together.
**Mudhole**- A small manhole, too small for access but used for washing out the boiler, either as an inlet for a water hose or as a drain to remove mud.
**Muffler**- An acoustic filter element used to reduce sound pressure levels inside a duct.
**Multi Element Array**- An array that consists of one or more arrays and is classified as to directivity.
**Multi Element Parasitic Array**- An array that contains two or more parasitic elements and a driven element.
**Multi Mode Fibre**- Optical fibre supporting more than one propagating mode.
**Multi Unit Tube**- An electron tube containing two or more units within the same envelope.
**Multiconductor**- More than one conductor, as in a cable.
**Multicouplers**- Couplers that patch receivers or transmitters to antennas.
**Multicrystalline**- Also known as Polycrystalline.
**Multiloop Servosystem**- A servosystem that contains more than one servo loop.
**Multimeter**- Electronic meter that displays voltage, current and resistance.
**Multimodal Distribution**- A distribution with more than one mode.
**Multinomial**- An algebraic expression consisting of 2 or more terms.
**Multiple**- The integer b is a multiple of the integer a if there is an integer d such that b=da.
**Multiple Bond**- Sharing of more than one electron pair between bonded atoms.
**Multiple Disc Clutch**- Multiple plates on input and output shafts are brought together to transmit torque. The multiple plates increases the frictional area.
**Multiple Thread Screw**- A screw made of two or more threads to provide an increased lead with a specified pitch.
**Multiples**- The product of multiplying a number by a whole number. The multiples of 3 are 6, 9, 12, 15,…
**Multiplexer**- A mechanical or electrical device for time sharing or a circuit.
**Multiplexing**- A method for simultaneous transmission of two or more signals over a common carrier wave.
**Multiplicand**- In the equation x = mn, m and n are the multiplicands since they are the two objects being multiplied together.
**Multiplication**- In arithmetic, multiplication of one number, a, by another, b, consists of adding a to itself b times.
**Multiplication Factor**- The number of times something is multiplied.
**Multiplication Rule**- The probability that events A and B both occur, is equal to the conditional probability that A occurs given that B occurs, times the unconditional probability that B occurs.
**Multiplicative Identity**- The number 1 is the multiplicative identity.
**Multiplicative Inverse**- The number that when multiplied by the original number will result in a product of one.
**Multivibrator**- A building block in which the output is either High or Low. There are three foms of multivibrator: Monostable, bi-stable and astable. The monostable has only one stable state, the bi-stable has two stable states and the astable is free-running (no stable states).
**Mumetal**- An alloy of high magnetic permeability containing up to 78% nickel with iron, copper and manganese.
**Muntz Metal**- Stonger than normal brass and used for castings and hot worked items. 60 % Copper 40 % Zinc
**Muon**- A type of lepton; often called a heavy electron.
**Muon Chamber**- The outer layers of a particle detector capable of registering tracks of charged particles.
**Murdock, William**- Built first steam powered lorry in 1784 and invented gas lighting.
**Muriatic Acid**- Ancient name for Hydrochloric Acid.
**Music Wire**- Another name for piano wire, a high quality steel wire used for making springs.
**Musical Twelfth**- The third-harmonic of a tone, which equals one octave and a fifth. Hence, twelfth and not 13 because you don′t count the original tone.
**Mustard Gas**- Common name for Dichlorodiethyl Sulphide a gas used in warfare.
**Mutual Conductance**- The ratio of the current at the output port and the voltage at the input ports.
**Mutual Flux**- The total flux in the core of a transformer that is common to both the primary and secondary windings.
**Mutual Inductance**- A circuit property existing when the relative position of two inductors causes the magnetic lines of force from one to link with the turns of the other.
**Mutual Interference**- The condition resulting when electronic systems degrade each other on a reciprocal basis.