How do you decide what size of electrical wire do you need?

The proper size of wires mainly depends on the amount of load current & voltage supplied as well as the length of the cable. Usually, the voltage drop in cables should not be greater then 2.5% of the supply.

• Measure the supply voltage.
• Calculate its 2.5% allowable voltage drop.
• Measure the required length of the cable in meters.
• Divide the allowable voltage drop with the length.
• The resultant is the max allowable voltage-drop per meter & your required cable size should have a lower voltage drop than this.
• Calculate your load current.

The cable charts provide this info such as voltage-drop per meter, current capacity, cable size, etc. match your calculation with the chart & find you required cable size. 

Define the term Capacitance and Inductance

Capacitance: capacitance is the ability of a component to store charge between two plates when there is a potential difference applied. It is denoted by C & it is measured in Farads F.

Inductance: inductance is the ability of a conductor to resist or oppose any change in the current. The current generates a magnetic field whose strength varies with the current. It is denoted by L & is measured in Henry H.