Browse Questions
Thermodynamics

# An ideal gas is filled in a closed rigid and thermally insulated container . A coil of 100 oms resistor carrying a current of 1 A for 5 minutes supplies heat to the gas . The change in the internal energy of the gas is

$(a)\;10\;KJ\qquad(b)\;20\;KJ\qquad(c)\;30\;KJ\qquad(d)\;0\;KJ$

Answer : $30\;KJ$
Explanation :
Heat supplied : $\; \bigtriangleup Q = I^2 R t$
$= 1 \times 100 \times 5 \times 60$
$= 30 KJ$
Since no change in volume . W =0
Therefore , $\; \bigtriangleup Q = \bigtriangleup u$
Therefore , $\bigtriangleup u = 30 \;KJ$