OBT3 COMPREHENSIVE EXAMINATION
TEST 2026 VERIFIED QUESTIONS AND
ANSWERS GRADED A+
●● approximately 96% to 99.75% of the fuel oil is composed of:
a) methane and propane
b)sulphur, oxygen and nitrogen
c) hydrogen and carbon
d)manufactured oil. Answer: c) hydrogen and carbon
●● that two general categories of refined fuel oils are:
a) distillates and residuals
b)light and dark
c)natural and manufactured
d)cracked and uncracked. Answer: a) distillates and residuals
●● true or false
kerosene is classified separately from fuel oil but considered as fuel oil
under the fuel oil code. Answer: true
●● what are the 6 grades of fuel oil established by Canadian standards
and their common applications. Answer: gas --> 1-5
,gasoline --> 6-10
leerosene --> 11-16
light fuel oil --> 13-17
heavy fuel oil --> 18-32
residuals --> 28-70
●● degrees of API gravity is a measurement scale of a fuel oil's
____________. Answer: density or weight
●● what is the API range of no. 2 fuel oil. Answer: 30 to 36
●● the commonly accepted heat valve of no.2 fuel oil is __________
btu/U.S.. Answer: 140,000
●● if the input rating of an appliance is 91,000 btu/h, the correct nozzle
size would be:
a).50 gph
b).60 gph
c).65 gph
d).75 gph. Answer: .65 gph
●● viscosity is a measure of a fluid's:
a) density
, b) heat content
c) resistance to flow
d) colour. Answer: c) resistance to flow
●● a fuel oil's viscosity _________ (increases or decreases) as the
temperature of the oil decreases. Answer: increases
●● the distillate characteristics of a fuel oil indicate its:
a) density
b) volatility and ability to vaporize
c)viscosity
d) flashpoint and fire point. Answer: b) volatility and ability to vaporize
●● true or false
liquid fuel oil will burn
explain. Answer: false
only vapours can burn
●● define combustion. Answer: rapid oxidation of a fuel creating heat
and light
●● what are the 3 components required for combustion.. Answer:
oxygen, ignition heat , fuel
TEST 2026 VERIFIED QUESTIONS AND
ANSWERS GRADED A+
●● approximately 96% to 99.75% of the fuel oil is composed of:
a) methane and propane
b)sulphur, oxygen and nitrogen
c) hydrogen and carbon
d)manufactured oil. Answer: c) hydrogen and carbon
●● that two general categories of refined fuel oils are:
a) distillates and residuals
b)light and dark
c)natural and manufactured
d)cracked and uncracked. Answer: a) distillates and residuals
●● true or false
kerosene is classified separately from fuel oil but considered as fuel oil
under the fuel oil code. Answer: true
●● what are the 6 grades of fuel oil established by Canadian standards
and their common applications. Answer: gas --> 1-5
,gasoline --> 6-10
leerosene --> 11-16
light fuel oil --> 13-17
heavy fuel oil --> 18-32
residuals --> 28-70
●● degrees of API gravity is a measurement scale of a fuel oil's
____________. Answer: density or weight
●● what is the API range of no. 2 fuel oil. Answer: 30 to 36
●● the commonly accepted heat valve of no.2 fuel oil is __________
btu/U.S.. Answer: 140,000
●● if the input rating of an appliance is 91,000 btu/h, the correct nozzle
size would be:
a).50 gph
b).60 gph
c).65 gph
d).75 gph. Answer: .65 gph
●● viscosity is a measure of a fluid's:
a) density
, b) heat content
c) resistance to flow
d) colour. Answer: c) resistance to flow
●● a fuel oil's viscosity _________ (increases or decreases) as the
temperature of the oil decreases. Answer: increases
●● the distillate characteristics of a fuel oil indicate its:
a) density
b) volatility and ability to vaporize
c)viscosity
d) flashpoint and fire point. Answer: b) volatility and ability to vaporize
●● true or false
liquid fuel oil will burn
explain. Answer: false
only vapours can burn
●● define combustion. Answer: rapid oxidation of a fuel creating heat
and light
●● what are the 3 components required for combustion.. Answer:
oxygen, ignition heat , fuel
