Humblebee, I am at a loss to under the use of a 10 Ampere, 12 Volt Diode, for use in
"Variable Voltage. Application - Output Stage"
Anyways, I will move on an try to revert to your Query:
"Suggest me a diode of 12V that has the least resistance. It should be of good quality."
Almost all easily available diodes are
a. Silicon Diodes
or
b. Schottky Diodes
Silicon Diodes have a Forward voltage Drop of approx 0.67 Volts. This means that 0.67 Volts will be Dropped across the Diode when it conducts. This 0.67 Volts drop is almost constant irrespective of the current flowing through the diode (eg 0.5 Amperes or 10 Amperes).
Hence diodes are Not classified by their resistance, but by their Forward Voltage Drop.
You could use a general purpose 10 Ampere Silicon Diode like the
10A10 (10 Amperes Current with a Max reverse voltage of 1000 V).
You can ALWAYS use a diode of higher voltage (Peak Inverse Voltage - PIV or Reverse Voltage, this is NOT the Forward Voltage) and current rating. The Price difference between a 50 Volt & 1000 Volt diode is often less than 15%, so shops often just stock and sell the 1000 Volt diode.
If you are Hell bent on shaving off a few millivolts forward drop, consider a Schottky Diode like the
STPS 10456 which will give you a slightly lower Forward voltage drop of 0.57 Volts.