a closed system undergoes a cyclic process returning to its initial state what can be said about the net work done wnet by the system over the entire

HESI A2

HESI A2 Physics

1. A closed system undergoes a cyclic process, returning to its initial state. What can be said about the net work done (Wnet) by the system over the entire cycle?

A. Wnet is always positive.
B. Wnet is always negative.
C. Wnet can be positive, negative, or zero.
D. Wnet is equal to the total heat transferred into the system (dQ ≠ 0 for a cycle).

Correct answer: C

Rationale: For a closed system undergoing a cyclic process and returning to its initial state, the net work done (Wnet) over the entire cycle can be positive, negative, or zero. This is because the work done is determined by the area enclosed by the cycle on a P-V diagram, and this area can be above, below, or intersecting the zero work axis, leading to positive, negative, or zero net work done. Choice A is incorrect because Wnet is not always positive; it depends on the specific path taken on the P-V diagram. Choice B is incorrect as Wnet is not always negative; it varies based on the enclosed area. Choice D is incorrect because Wnet is not necessarily equal to the total heat transferred into the system; it depends on the specifics of the cycle and is not a direct relationship.

2. Which of the following is a colligative property of a solution?

A. Freezing point depression
B. Viscosity
C. Surface tension
D. Boiling point elevation

Correct answer: A

Rationale: A colligative property is a property that depends on the number of solute particles in a solution, not on the identity of the solute particles. Freezing point depression is one such property, where adding a solute to a solvent lowers the freezing point of the solution compared to the pure solvent. This phenomenon occurs because the presence of solute particles disrupts the formation of the regular crystal lattice structure, requiring a lower temperature for solidification to occur. Choices B, C, and D are not colligative properties. Viscosity and surface tension are not dependent on the number of solute particles but on intermolecular forces and molecular interactions. Boiling point elevation is another colligative property, but in this case, the question asked for a colligative property of a solution, making freezing point depression the correct answer.

3. Where is a herniated lumbar disc most likely to cause pain?

A. Along the radial nerve
B. Within the spinal cord
C. Along the sciatic nerve
D. Along the tibial nerve

Correct answer: C

Rationale: A herniated lumbar disc is most likely to cause pain along the sciatic nerve. The sciatic nerve is a long nerve that extends from the lower back down the back of each leg. Compression of the sciatic nerve by a herniated disc can lead to symptoms such as pain, numbness, tingling, or weakness that radiates down the leg. This condition is commonly referred to as sciatica. Choices A, B, and D are incorrect because a herniated lumbar disc typically affects the sciatic nerve, not the radial nerve, spinal cord, or tibial nerve.

4. Choose the best summary of the passage about Sunny-Side Up.

A. Light-skinned people need a maximum of 15 minutes a day in direct sunlight to achieve the benefits of the sun’s rays.
B. Spending too much time indoors can wreak havoc with your circadian rhythms, leach vitamin D from your bones, and damage your immune system.
C. Although negative effects of sunlight are well known, people should be aware that some sunlight is necessary and beneficial.
D. You can avoid direct sunlight but still reap the benefits of a day in the sun by using sunscreen or tinted glass.

Correct answer: C

Rationale: The best summary captures the essence of the passage, which acknowledges the well-known negative effects of sunlight while also emphasizing the necessity and benefits of sunlight exposure. C accurately reflects this balanced view, making it the most appropriate choice.

5. Which system does the gall bladder belong to?

A. endocrine system
B. urinary system
C. digestive system
D. nervous system

Correct answer: C

Rationale: The gall bladder is part of the digestive system. Its primary function is to store and concentrate bile produced by the liver and release it into the small intestine to aid in the digestion of fats. This process facilitates the breakdown and absorption of fats from the food we consume. Choices A, B, and D are incorrect as the gall bladder is not associated with the endocrine, urinary, or nervous systems.