# Resistor colour codes #### 4 Band resistor colour coding

On a resistor which has four bands of color, the first and second bands represent a two digit number. This can be found by looking at which number value the colours represent. In the Figure below, the first band is brown and the second is black. This gives use 10 as our two digit number. Next, you look at the third colour, which represents the multiplier. You take this value and multiply it by the two digit number. In this case, it would be 10 x 100Ω. This would give us a resistor value of 1kΩ.

####  # Wavelength & Frequency calculations

This equation allows you to calculate wavelength from frequency, and frequency from wavelength.  In this equation: (lambda) represents wavelength (in metres).

c         represents the velocity of light (which is approximately 3.00×108 m/s).

f         represents frequency (in hertz). Wavelength is the distance between two peeks of the signal.

frequency is the number of oscillations in one second. # Ohm’s Law

Ohm’s law is the basis behind electronic equations. It establishes a relationship between voltage, current, and resistance. He stated the following relationship: In addition to this, we can deduce two more equations from this one.  Because of this relationship, it is possible to calculate any of these values, with just two of the three.