Nursing Elites

1. Which of the following describes a reflex arc?

• A. The storage and recall of memory
• B. The maintenance of visual and auditory acuity
• C. The autoregulation of heart rate and blood pressure
• D. A stimulus and response controlled by the spinal cord

Correct answer: D

Rationale: Choice D correctly describes a reflex arc. A reflex arc is a neural pathway that controls a reflex action. It involves a specific sequence of events that occur in response to a stimulus, which is rapidly and involuntarily processed by the spinal cord. The spinal cord coordinates the quick processing of sensory input and the generation of a motor response without involving the brain, allowing for rapid protective responses. Choices A, B, and C are incorrect because they do not accurately describe a reflex arc. A reflex arc is specifically related to the rapid and involuntary response to a stimulus through neural pathways involving the spinal cord, not memory storage, visual and auditory acuity maintenance, or heart rate and blood pressure autoregulation.

2. Which of the following is a strong base commonly used in cleaning products?

• A. Sodium hydroxide (NaOH)
• B. Ammonium hydroxide (NH₄OH)
• C. Calcium hydroxide (Ca(OH)₂)
• D. Potassium hydroxide (KOH)

Correct answer: A

Rationale: Sodium hydroxide (NaOH) is a strong base commonly used in cleaning products due to its effectiveness in breaking down grease and fats. It is known for its corrosive properties and is commonly found in drain cleaners and oven cleaners. While ammonium hydroxide, calcium hydroxide, and potassium hydroxide are also bases, they are not as strong as sodium hydroxide and are not as commonly used in cleaning products. Ammonium hydroxide is more commonly found in household cleaning products for its disinfectant properties, calcium hydroxide is used in agriculture and construction, and potassium hydroxide is often used in industries like soap manufacturing and biodiesel production.

3. Which of the following salt solutions is most likely to conduct electricity well?

• A. A saturated solution
• B. A concentrated solution of a strong electrolyte
• C. A dilute solution of a weak acid
• D. A mixture of a neutral compound and water

Correct answer: B

Rationale: A concentrated solution of a strong electrolyte is most likely to conduct electricity well. Strong electrolytes completely dissociate into ions in solution, allowing for the flow of electric current. This high concentration of ions in the solution enhances its conductivity, making it a better conductor compared to other options. A saturated solution, although containing dissolved ions, may not have a high enough concentration to conduct electricity effectively. A dilute solution of a weak acid is a poor conductor as weak acids only partially dissociate into ions. A mixture of a neutral compound and water does not contain free ions necessary for conducting electricity.

4. Who is credited with the discovery of nuclear fission?

• A. Marie Curie
• B. Albert Einstein
• C. Enrico Fermi
• D. Ernest Rutherford

Correct answer: C

Rationale: Enrico Fermi is credited with the discovery of nuclear fission. In 1934, Fermi bombarded uranium with neutrons, leading to the splitting of the uranium nucleus and the release of energy. This groundbreaking discovery laid the foundation for the development of nuclear power and weapons. Marie Curie is known for her pioneering research on radioactivity, but she did not discover nuclear fission. Albert Einstein made significant contributions to physics, including the theory of relativity, but he was not credited with the discovery of nuclear fission. Ernest Rutherford conducted the famous gold foil experiment and made contributions to the understanding of the atom's structure, but he did not discover nuclear fission.

5. Which type of lens focuses parallel light rays to a single point?

• A. Concave lens
• B. Convex lens
• C. Cylindrical lens
• D. Plano lens

Correct answer: B

Rationale: A convex lens focuses parallel light rays to a single point by causing them to converge. This lens is thicker in the center than at the edges, which helps in converging the light rays. Convex lenses are commonly used for tasks like magnification and focusing due to their ability to bring distant light rays to a single focal point. Choice A, the concave lens, diverges light rays rather than converging them, making it incorrect. Choice C, the cylindrical lens, is designed to focus light along one axis rather than converging parallel light rays to a single point. Choice D, the plano lens, has no curvatures to bend or focus light rays, so it does not converge parallel light rays.

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