# calculating inductance formula

what is the formula for caculating inductance on the basis of

1)No of turns. 2)Diameter of the wire 3)Diameter of the wounded circle. ?

how to calculate the capacitance value in ceramic capacitor ? which is given as 104 or 103 or 102 etc.

Give me the equation or calculation technique....

For ceramic capacitor values, the first two digits are the value, the third digit is the tens multiplier, in picofarads.

Thus:

104 = 10 * 10000 = 100 nF = 0.1 microfarad
102 = 10 * 100 = 1000 pf = 1 nanofarad
183 = 18 * 1000 = 18 nF = 0.018 microfarad

A simple lookup table exists here.

For the inductance calculation, the question does not specify whether self-inductance of a coil with an air-core or some other core is required, or mutual inductance of multiple coils. In any case, this Wikipedia link provides calculation methods; On the assumption that a single coil with an air core is under discussion, this formula will serve the purpose.

For a single layer solenoid, or a circular loop, the relevant formulae are listed in the table on that page.