Nursing Elites

1. 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.

2. Which of the following is the cartilaginous flap that protects the larynx from water or food while still allowing the flow of air?

• A. epiglottis
• B. bronchioles
• C. epithelium
• D. tongue

Correct answer: A

Rationale: The epiglottis is the cartilaginous flap that protects the larynx from water or food while still allowing the flow of air. When we swallow, the epiglottis covers the entrance to the larynx, preventing food or liquid from entering the airway and instead directing them towards the esophagus for digestion. Choice B, bronchioles, are small airway branches within the lungs and are not involved in protecting the larynx from food or water. Choice C, epithelium, refers to the tissue that lines the surfaces of organs and structures in the body, but it is not the specific structure that protects the larynx as described. Choice D, tongue, plays a role in taste, speech, and swallowing, but it is not the cartilaginous flap that protects the larynx.

3. What is the function of the epiglottis?

• A. Produces saliva
• B. Senses taste
• C. Prevents food from entering the windpipe
• D. Filters blood

Correct answer: C

Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the windpipe (trachea) during swallowing to prevent food and liquids from entering the airway. This action ensures that food and liquids are directed to the esophagus and down into the stomach, rather than entering the respiratory system, which could lead to choking or aspiration pneumonia. Options A, B, and D are incorrect as they describe functions of other structures in the body that are not related to the role of the epiglottis.

4. Which of the following terms means toward the front of the body?

• A. Superior
• B. Anterior
• C. Inferior
• D. Posterior

Correct answer: B

Rationale: The correct answer is B: Anterior. The term 'anterior' specifically refers to the front of the body. In anatomical terms, anterior is the opposite of posterior, which means toward the back of the body. Superior and inferior, choices A and C, respectively, refer to top and bottom directions, not front and back. Therefore, 'Anterior' is the most appropriate term for describing a position toward the front of the body.

5. What is the SI unit of measurement for work?

• A. Newton-meter (N·m)
• B. Joule (J)
• C. Watt (W)
• D. Meter per second (m/s)

Correct answer: B

Rationale: The correct answer is B: Joule (J). Work is defined as the amount of energy transferred by a force acting through a distance. The Joule is the unit used to measure this energy transfer. Choice A, Newton-meter (N·m), is the unit for torque, not work. Choice C, Watt (W), is the unit of power, not work. Choice D, Meter per second (m/s), is a unit for speed or velocity and is not related to work.

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