Month: January 2023

Positive and negative terminals in a polarized capacitor?

All electrolytic capacitors are polarized, and carry markings to identify polarity of terminations.

Most small aluminium electrolytic capacitors carry a stripe on negative terminal side. In case of axial lead aluminium electrolytic capacitor, the stripe also carries arrow marks to point to negative terminal.

In addition, when lead wire are used as output terminals, negative terminal lead is shorter. So it çan be identified independent of other markings.

Large aluminium electrolytic capacitor with terminal disc has often red mark at base of + terminal.

In case of tantalum axial capacitor, often a + mark is placed to identify positive terminal.

What is polarization in a capacitor?

Not all capacitors are polarized, ones that are will be clearly marked with + and – where the leads go into the case.

Polarized capacitors are a type of capacitor called an electrolytic capacitor in which a chemical reaction on the surface of the capacitor’s anode forms an oxide layer that serves as the capacitor’s dielectric separator. Reversing the polarity would cause the oxide layer to dissolve causing the capacitor to short circuit, hence the need to be polarized.

Electrolytic capacitors are typically cylindrical with both leads coming out of one end of the can. They can be quite large. Failed electrolytic capacitors can split or even explode.

Cable Selection

What does polarized capacitors mean?

A polarized capacitor has a dielectric material in it similar to the acid in a battery.

Capacitors consist of a sandwich of two conductors separated by an insulator. In a polarized capacitor the insulating material is a dielectric, meaning it becomes a dipole when the capacitor is charged.

Ordinary capacitors do not have a positive and negative side, but polarized capacitors do have a positive side and a negative side. When they are connected to a circuit you must take care to connect the positive side to positive and the negative side to negative. Failure to connect it properly could damage the capacitor. Under some circumstances it could overheat and be dangerous.

The large capacitance of electrolytic capacitors makes them particularly suitable for passing or bypassing low-frequency signals, and for storing large amounts of energy. They are widely used for decoupling or noise filtering in power supplies and DC link circuits for variable-frequency drives, for coupling signals between amplifier stages, and storing energy as in

Cable Selection

Since There are different sizes and types of cables available in market, we have to do cable selection to be used at specific location according to the usage. Types of cables are as follows:-

  • Copper Cable
  • Alluminium Cable

Also Copper and Aluminium cables are available in different sizes like 1 sq.mm to 300 sq.mm and different sizes carry different currents and also different gland sizes. One can do cable selection to be used after checking the current taken by cable which can be selected easily from below tables

From above table one can easily learn about copper cable size from 1.5sq.mm to 35 sq.mm their gland size, current carrying capacity and breaker to be used for particular cable.

Godown Wiring

Also we are providing a table of copper cable size 50sq.mm to 300sq.mm having complete specifications of gland size, current carrying capacity and breaker size. Kindly have a look

So In this article you have learned about copper cables and easily perform cable selection for particular job from these tables.

Youtube Channel :- Electrical Stuff 4u

Does fire conduct electricity?

Fire basically conducts electricity the same way salty water does: both contain some concentration of charged particles that are free to move.
Water contains some concentrations of ions and protons (H++ protons). When there is a voltage difference, the ions will move according to their charge.
The hot gas of the flame contains positively charged ions and electrons, which will move in the same way as the ions in the water. The reason there are ions is that the heat of the gas is such that some of the electrons can free themselves from the attraction of their atoms.

For sure! Fire is a plasma, and plasmas have freely-moving charged particles within them. Anything that has freely-moving charged particles conducts electricity.

So metals, which have a sea of mobile negatively-charged electrons on their surface, conduct electricity. And saltwater…