UNIT 1 : General Princples Flashcards
1.
For which one of the following apparatus sub-groups is ethylene the representative gas?
I
IIA
IIB
IIC
IIB
2.
Which one of the following is not required for combustion of a flammable material?
Oxygen;
An enclosure;
An ignition source;
Fuel
An Enclosure
3.
Spontaneous ignition of a flammable mixture occurs at?
Its fire point;
Its upper ignition temperature;
Its flash point;
Its ignition temperature
Its ignition temperature.
4.
The number of temperature classes for marking explosion protected equipment?
8
4
6
5
6
5.
Which one of the following statements represents the presence of a flammable mixture in zone 0?
Not likely to be present in normal operation;
Not present during normal operation;
Present continuously, or for long periods, or frequently ;
Present in normal operation occasionally.
Present continuously, or for long periods, or frequently.
6.
An area classification diagram will represent Zone 1 by which one of the following?
Cross-hatching at 45 degrees;
Small circles;
Lines angled at 45 degrees;
As indicated by drawing key symbols.
As indicated by drawing key symbols.
7.
The property of a flammable material which is considered in order to determine the appropriate T-rating for equipment is?
The upper flammable limit of the material;
The material sub-division;
The ignition temperature of the material;
The flashpoint of the material
The ignition temperature of the material.
8.
Equipment marked T6 will have a maximum surface temperature of?
450°c;
300°c;
85°C;
100°c
85°C
9.
The numbers after the letters IP in the ingress protection codes represent?
Solid particles and mechanical protection;
Supply voltage and water pressure;
Solid particles and water;
Dust particle size and condensation.
Solid particles and water
10.
Which one of the following sub-divisions is necessary for equipment in an acetylene hazard?
IID
IIC
IIB
IIA
IIC
11.
The T-rating, e.g.
T5, marked on the certification label of equipment indicates that the surface temperature of the equipment?
Will not reach the flashpoint temperature of the gas in normal operation;
Is designed to reach the temperature represented by the T-rating;
Will not reach the ignition temperature of any dust or gas in normal operation;
Will not exceed the temperature represented by the T-rating during normal or specified fault conditions
Will not exceed the temperature represented by the T-rating during normal or specified fault conditions
12.
Which one of the following sub-divisions hydrogen belong?
IIA
IIB
IIC
I
IIC
13.
Equipment marked only (without a letter A, B or C) is?
Suitable for use in areas where llA or IIB gases are present;
Suitable for use in any Group II gases or vapours;
Suitable for use where only IIA gases are present;
Not suitable for use in hazardous areas
Suitable for use in any Group II gases or vapours
14.
In which one of the following zones is an explosive gas/air mixture likely to occur in normal operation occasionally?
Zone 21
Zone 2
ZONE 1
Zone 0
Zone 1.
15.
A zone 2 area is where an explosive gas/air mixture is?
Is likely to be present during normal operation occasionally;
Continuously present or present for long periods;
Not present during normal operation;
Not likely to occur in normal operation, and if it does occur is likely to do so
only infrequently and will exist for a short period only
Not likely to occur in normal operation, and if it does occur is likely to do so only infrequently and will exist for a short period only.
