Quiz for First law

Q1: The first law of thermodynamics is a statement of:

A. Conservation of mass B. Conservation of energy C. Entropy increase D. Heat flow

Q2: In the first law, the change in internal energy (ΔU) equals:

A. Heat added + Work done by system B. Heat added - Work done by system C. Heat absorbed - Work done on system D. Heat absorbed + Work done on system

Q3: When a system does work on the surroundings, the internal energy:

A. Increases B. Decreases C. Remains same D. Becomes zero

Q4: If heat is added to the system and no work is done, internal energy:

A. Increases B. Decreases C. Remains same D. Becomes zero

Q5: Which is a state function?

A. Work B. Heat C. Internal energy D. Path

Q6: Work done by a gas expanding against constant external pressure is:

A. w = -PΔV B. w = PΔV C. w = 0 D. w = ΔU

Q7: In an adiabatic process, heat exchange (q) is:

A. Positive B. Negative C. Zero D. Variable

Q8: The first law of thermodynamics applies to:

A. Only closed systems B. Only open systems C. All systems D. Only isolated systems

Q9: Which quantity is NOT a form of energy?

A. Heat B. Work C. Internal energy D. Volume

Q10: In exothermic reaction, heat flow (q) is:

A. Positive B. Negative C. Zero D. Cannot be determined

Q11: Which process involves positive work done on the system?

A. Gas expansion B. Gas compression C. Isothermal expansion D. Adiabatic expansion

Q12: If ΔU = 0 in a process, then:

A. q = w B. q = -w C. q = 0 D. w = 0

Q13: Which is true for a cyclic process?

A. ΔU > 0 B. ΔU < 0 C. ΔU = 0 D. ΔU = q + w

Q14: The unit of internal energy in SI is:

A. Joule B. Calorie C. Kelvin D. Watt

Q15: The first law of thermodynamics is also known as:

A. Law of conservation of energy B. Law of entropy C. Boyle’s law D. Charles’s law

Q16: Work done on the system is:

A. Positive B. Negative C. Zero D. Variable

Q17: Heat absorbed by the system is:

A. Positive B. Negative C. Zero D. Variable

Q18: During isochoric process, work done is:

A. Positive B. Negative C. Zero D. Variable

Q19: If no heat exchange occurs, the first law simplifies to:

A. ΔU = 0 B. ΔU = w C. ΔU = -w D. ΔU = q

Q20: The first law explains the relationship between:

A. Heat, work, and temperature B. Heat, work, and internal energy C. Pressure, volume, and temperature D. Entropy and energy