A coppers hell closed at one end and containing a charge of detonating compound, which is ignited by electric current or the spark of a fuse; used for detonating high explosives.

Related Terms


A blasting cap ignited by electric current and not by a spark.


  1. Metallic wire or ribbon which is heated in an incandescent lamp to produce light, by passing an electric current through the filament. 2. A cathode made of resistance wire or ribbon, through which an electric current is sent to produce the high temperature filament filamentary cathode required for emission of electrons in a thermionic tube. Also known as directly heated cathode; filamentary cathode; filament-type cathode.


Any plot, graph, or tracing produced by the action of an electric current on prepared sensitized paper (or other chart material) or by means of an electrically controlled stylus or pen.


An electron tube characterized by the interaction of electrons with the electric field of circuit element in crossed steady electric and magnetic fields to produce an alternating current power output. It is used to generate high power output in the ultra-high and super-high frequency bands.


A flash, caused by an electric current ionizing a gas or vapor.


The frequency at the high end of a transistor's range at which current amplification drops 3 decibels below its low-frequency value.


A crystalline substance which allows electric current to pass in only one direction


A cable carrying an electric current for degaussing a vessel


Electrode, without metallic connection with the current supply, one face of which acts as anode surface and the opposite face as a cathode surface when an electric current is passed through a cell.


An instrument for measuring the magnitude of a small electric current or for detecting the presence or direction of such a current by means of motion of an indicator in a magnetic field.

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