Aviation Basics

Nickel-Cadmium Batteries Chemistry and Construction Active materials in nickel-cadmium cells (Ni-Cad) are nickel hydrate (NiOOH) in the charged positive plate (Anode) and sponge cadmium (Cd) in the charged negative plate (Cathode). The electrolyte is a potassium hydroxide (KOH) solution in concentration of 20–34 percent by weight pure KOH in distilled water. Sintered nickel-cadmium cells have … Read more

Primary Cell The dry cell is the most common type of primary-cell battery and is similar in its characteristics to that of an electrolytic cell. This type of a battery is basically designed with a metal electrode or graphite rod acting as the cathode (+) terminal, immersed in an electrolytic paste. This electrode/electrolytic build-up is … Read more

Perhaps the most serious trouble in a circuit is a direct short. The term “direct short” describes a situation in which some point in the circuit, where full system voltage is present, comes in direct contact with the ground or return side of the circuit. This establishes a path for current flow that contains no … Read more

Fixed Resistor Fixed resistors have built into the design a means of opposing current. [Figure 1] The general use of a resistor in a circuit is to limit the amount of current flow. There are a number of methods used in construction and sizing of a resistor that control properties, such as resistance value, the … Read more

Power in an Electrical Circuit This section covers power in the DC circuit and energy consumption. Whether referring to mechanical or electrical systems, power is defined as the rate of energy consumption or conversion within that system—that is, the amount of energy used or converted in a given amount of time. From the scientific discipline … Read more

While wire of any size or resistance value may be used, the word “conductor” usually refers to materials that offer low resistance to current flow, and the word “insulator” describes materials that offer high resistance to current. There is no distinct dividing line between conductors and insulators; under the proper conditions, all types of material … Read more

Magnetism is defined as the property of an object to attract certain metallic substances. In general, these substances are ferrous materials; that is, materials composed of iron or iron alloys, such as soft iron, steel, and alnico. These materials, sometimes called magnetic materials, include at least three nonferrous materials: nickel, cobalt, and gadolinium, which are … Read more

In 1820, the Danish physicist, Hans Christian Oersted, discovered that the needle of a compass brought near a current carrying conductor would be deflected. When the current flow stopped, the compass needle returned to its original position. This important discovery demonstrated a relationship between electricity and magnetism that led to the electromagnet and to many … Read more

Electricity is often described as being either static or dynamic. The difference between the two is based simply on whether the electrons are at rest (static) or in motion (dynamic). Static electricity is a buildup of an electrical charge on the surface of an object. It is considered “static” due to the fact that there … Read more

Matter Matter can be defined as anything that has mass and volume and is the substance of which physical objects are composed. Essentially, it is anything that can be touched. Matter is what all things are made of; whatever occupies space, has mass, and is perceptible to the senses in some way. Weight is an … Read more