If 50 calorie are added to a system and system does work of 30 calorie on surroundings, the change in internal energy of system is:
20 cal.
50 cal.
40 cal.
30 cal.
As learnt in
IUPAC Sign Convention -
Any type of energy (Heat, Work ) given to system is positive
Any type of energy take out from the system
- wherein
i.e. 10 J work done on the system
i.e. 10 J released by the system
First law of Thermodynamics -
Energy of universe is always conserved or total energy of an isolated system is always conserved
- wherein
Internal Energy
Heat
work
(work is done by the system, so w= -ve)
= 50 -30
= 20 cal
Option 1)
20 cal.
correct
Option 2)
50 cal.
Incorrect
Option 3)
40 cal.
Incorrect
Option 4)
30 cal.
Incorrect