Nursing Elites

1. Which of the following is a strong acid?

• A. Acetic acid (CH₃COOH)
• B. Hydrochloric acid (HCl)
• C. Citric acid
• D. Carbonic acid (H₂CO₃)

Correct answer: B

Rationale: Hydrochloric acid (HCl) is a strong acid because it completely ionizes in water to produce hydrogen ions, leading to a high concentration of H⁺ ions in solution. This characteristic makes it a strong acid. Acetic acid (CH₃COOH), citric acid, and carbonic acid (H₂CO₃) are weak acids as they only partially ionize in water, resulting in a lower concentration of H⁺ ions compared to strong acids. Therefore, hydrochloric acid is the correct choice as a strong acid.

2. Which neuromuscular system controls voluntary movement?

• A. Autonomic
• B. Somatic
• C. Sympathetic
• D. Parasympathetic

Correct answer: B

Rationale: The correct answer is B, Somatic. The somatic nervous system controls voluntary movements of skeletal muscles. It is responsible for carrying sensory and motor information to and from the central nervous system. Choices A, C, and D are incorrect. The autonomic nervous system (choice A) controls involuntary functions such as heart rate and digestion. The sympathetic (choice C) and parasympathetic (choice D) nervous systems are subdivisions of the autonomic nervous system and are responsible for the body's fight-or-flight response and rest-and-digest functions, respectively.

3. According to the wave theory of light, the bright fringes observed in a double-slit experiment correspond to:

• A. Constructive interference
• B. Destructive interference
• C. Increased diffraction
• D. Total internal reflection

Correct answer: A

Rationale: In a double-slit experiment based on the wave theory of light, the bright fringes are the result of constructive interference. Constructive interference occurs when light waves from the two slits arrive at a point in phase, reinforcing each other and creating a bright fringe. This reinforcement leads to the constructive addition of the wave amplitudes, resulting in a bright spot on the screen. Destructive interference, which would result in dark fringes, occurs when waves are out of phase and cancel each other out. Increased diffraction and total internal reflection are not related to the formation of bright fringes in a double-slit experiment. Therefore, the correct answer is constructive interference.

4. Muscle tissue is responsible for movement. Which type of muscle tissue is found in the heart?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. All of the above

Correct answer: C

Rationale: Cardiac muscle is the type of muscle tissue found in the heart. Unlike skeletal muscle and smooth muscle, cardiac muscle is striated and involuntary, meaning it contracts without conscious control. It forms the majority of the heart's structure and is essential for its rhythmic contraction to pump blood throughout the body. Skeletal muscle is attached to bones and responsible for voluntary movements, while smooth muscle is found in organs and blood vessels, controlling various involuntary functions like digestion and blood flow. Therefore, choices A (Skeletal muscle) and B (Smooth muscle) are incorrect as they are not the types of muscle tissue found in the heart.

5. A light ray travels from air (refractive index 1.00) into water (refractive index 1.33). What happens to its speed and direction?

• A. Speed increases, direction bends towards the normal.
• B. Speed increases, direction bends away from the normal.
• C. Speed decreases, direction bends towards the normal.
• D. Speed and direction remain unchanged.

Correct answer: C

Rationale: When a light ray travels from air (lower refractive index) to water (higher refractive index), its speed decreases due to the change in the medium. This is because light travels slower in denser mediums. As the light ray enters the denser medium, water in this case, it bends towards the normal (the line perpendicular to the surface of the water). This phenomenon is known as refraction. Choice A is incorrect as the speed of light decreases when entering a denser medium. Choice B is incorrect as the direction bends towards the normal, not away from it. Choice D is incorrect as the speed and direction of the light ray do change when moving from air to water.

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