Question

A tungsten light bulb is usually filled with some inert gases to a pressure of80 kPa at a temperature of 20 °C. The maximum internal pressure that thebulb can withstand is about 280 kPa. Find the temperature in °C of thegases at which the bulb bursts.

Answer 1

Given:

The initial pressure of the gas is,

`P_1=80\text{ kPa}`

The initial temperature is,

`T_1=20+273=293\text{ K}`

The final pressure is,

`P_2=280\text{ kPa}`

Let the final temperature be,

`T_2`

We know,

`\begin{gathered} (P_1)/(T_1)=(P_2)/(T_2) \\ T_2=(P_2T_1)/(P_1) \end{gathered}`

Substituting the values we get,

`\begin{gathered} T_2=(280*293)/(80) \\ T_2=1025\text{ K} \\ T_2=1025-273=752^(\circ)C \end{gathered}`

Hence the required temperature is 752 degrees celcius.