Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
SF6 gas convert into liquefied form at
10┬░C and 15 atm pressure
15┬░C and 15 atm pressure
20┬░C and 15 atm pressure
30┬░C and 15 atm pressure
10┬░C and 15 atm pressure
Sulfur Hexafluoride (SF6) gas is used in circuit breakers for its excellent arc-quenching and insulating properties. It liquefies under pressure, and its phase state is highly dependent on both temperature and pressure; at a typical pressure of 15 atm, the liquefaction temperature is approximately 10┬░C.
Sulfur Hexafluoride (SF6) gas is used in circuit breakers for its excellent arc-quenching and insulating properties. It liquefies under pressure, and its phase state is highly dependent on both temperature and pressure; at a typical pressure of 15 atm, the liquefaction temperature is approximately 10┬░C.
PsatтАЛ=f(T) тАФ The relationship between saturated vapor pressure and temperature for a substance
PV=ZnRT тАФ Real gas behavior equation where Z accounts for deviation from ideal gas behavior near liquefaction
The liquefaction of SF6 is governed by its phase diagram. In switchgear, keeping the gas in a gaseous state is critical to prevent insulation failure. As temperature drops, the saturated vapor pressure decreases. If the ambient temperature falls below the liquefaction point for a given pressure (15 atm), the gas turns into liquid, significantly reducing the pressure in the tank and impairing the dielectric strength of the circuit breaker.
SF6 is an electronegative gas used primarily in high-voltage switchgear.
Liquefaction at low temperatures leads to a drop in internal gas pressure, which reduces dielectric strength.
Circuit breakers often use heating elements to maintain the gas temperature above the liquefaction point.
SF6 is chemically inert, non-toxic, and non-flammable under normal operating conditions.
Superior arc quenching capabilities
High dielectric strength
High global warming potential
Liquefaction risk at low ambient temperatures
Gas Insulated Switchgear (GIS)
High voltage circuit breakers
The boiling point of SF6 at atmospheric pressure is approximately -63.8┬░C.
Option B, C, and D represent higher temperatures where SF6 remains in a stable gaseous state at 15 atm pressure, hence they are incorrect for the specific liquefaction threshold.
A is correct тАФ SF6 gas tends to reach its liquefaction point at 10┬░C when subjected to a pressure of 15 atm.
Always remember that SF6 pressure is temperature-compensated; a decrease in pressure reading during winter is often due to gas cooling rather than a leak.