> gal kas paaiskinsit kuom visgi skiriasi t8 ir t5 lempos?

  Rezultatai googlyje prasideda nuo:

Because the T5 lamp is only available in metric dimensions, and
since it can't be easily retrofitted into existing T8 or T12 fixtures

  O wikipedia sako:

T5 retrofit conversion: Conversion kits are available which will work
in existing fittings containing switch start, mains frequency fluorescent
lamp ballasts. The kits convert the fittings to use energy efficient,
high frequency ballasts and accommodate the smaller diameter T5 lamp.

-- 
  saimhe