First Law of Thermodynamics
Physics ⇒ Heat and Thermodynamics
First Law of Thermodynamics starts at 10 and continues till grade 12.
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Describe a real-life example where the First Law of Thermodynamics is applied.
Describe what happens to the internal energy of a system if it absorbs heat but does no work.
Explain the difference between state functions and path functions with examples relevant to the First Law of Thermodynamics.
Explain why heat and work are not state functions.
A gas expands at constant pressure, doing 400 J of work and absorbing 600 J of heat. What is the change in internal energy?
A gas is compressed by a piston, and 250 J of work is done on the gas. If the internal energy increases by 100 J, how much heat is exchanged and in which direction?
A gas is compressed in a cylinder by a piston. The gas releases 150 J of heat to the surroundings and the work done on the gas is 200 J. What is the change in internal energy of the gas?
A system does 100 J of work on its surroundings and its internal energy decreases by 250 J. How much heat was transferred to or from the system?
Which of the following equations correctly represents the First Law of Thermodynamics?
(1) ΔU = Q + W
(2) ΔU = Q - W
(3) Q = ΔU + W
(4) W = Q - ΔU
Which of the following is a state function?
(1) Work
(2) Heat
(3) Internal Energy
(4) Both 1 and 2
Which of the following is NOT a consequence of the First Law of Thermodynamics?
(1) Energy can be converted from one form to another
(2) Perpetual motion machines of the first kind are impossible
(3) Heat can flow from cold to hot spontaneously
(4) The total energy of an isolated system remains constant
Which of the following is NOT a path function?
(1) Work
(2) Heat
(3) Internal Energy
(4) All of the above
Fill in the blank: In an isochoric process, the work done by the system is __________.
Fill in the blank: The First Law of Thermodynamics is also known as the law of __________.
Fill in the blank: The First Law of Thermodynamics is not violated in any __________ process.
Fill in the blank: The mathematical expression for the First Law of Thermodynamics is ΔU = Q - __________.
True or False: In a cyclic process, the net change in internal energy of the system is zero.
True or False: The First Law of Thermodynamics applies only to closed systems.
True or False: The First Law of Thermodynamics can be used to calculate the efficiency of a heat engine.
True or False: The First Law of Thermodynamics can be used to determine the direction of heat flow.
