Nursing Elites

1. What is the difference between isometric and isotonic muscle contractions?

• A. Isometric involves movement, while isotonic does not.
• B. Isotonic involves shortening of muscle, while isometric maintains length.
• C. Isometric uses more energy, while isotonic uses less.
• D. Isotonic involves smooth muscle, while isometric involves skeletal muscle.

Correct answer: B

Rationale: The correct answer is B. Isometric contractions occur when the muscle generates tension without changing its length, while isotonic contractions involve the muscle changing length to move a load. In isotonic contractions, the muscle shortens to move a load, whereas in isometric contractions, the muscle contracts to hold a position without movement. Choice A is incorrect because isometric contractions do not involve movement, while choice C is incorrect as isotonic contractions typically require more energy due to movement. Choice D is incorrect because the type of muscle involved (smooth or skeletal) is not the defining factor between isometric and isotonic contractions.

2. Bone is primarily composed of which of the following inorganic materials?

• A. calcium
• B. magnesium
• C. collagen
• D. potassium

Correct answer: A

Rationale: Bone is primarily composed of calcium, making up about 70% of its inorganic content. Calcium is essential for bone strength and structure, playing a key role in maintaining bone health. Choice B, magnesium, while important for bone health, is found in smaller amounts in bones compared to calcium. Choice C, collagen, is a protein and is a major organic component of bone, not an inorganic material. Choice D, potassium, is an essential mineral for various bodily functions but is not a primary inorganic material found in bones.

3. What term describes the point where parallel rays of light converge or appear to diverge after passing through a lens or reflecting off a mirror?

• A. Aperture
• B. Focal length
• C. Refractive index
• D. Lens thickness

Correct answer: B

Rationale: The focal length is the term used to describe the point where parallel rays of light converge or appear to diverge after passing through a lens or reflecting off a mirror. It is a fundamental concept in optics that determines the behavior of light rays in optical systems. The focal length directly affects image formation, magnification, and focus. Options (A) Aperture, (C) Refractive index, and (D) Lens thickness are not specifically associated with the convergence or divergence of light rays in optical systems. Aperture refers to the opening through which light passes, refractive index is a measure of how much light bends when entering a medium, and lens thickness is unrelated to the convergence or divergence of light rays.

4. In a chemical reaction, the total amount of:

• A. Matter remains the same
• B. Matter increases
• C. Matter decreases
• D. Energy remains the same

Correct answer: A

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, only rearranged. This principle implies that the total amount of matter before and after a chemical reaction must remain constant, supporting the correct answer choice A. Choice B is incorrect because the total amount of matter does not increase in a chemical reaction; it is conserved. Choice C is incorrect as the total amount of matter does not decrease in a chemical reaction; it is conserved. Choice D is incorrect since the conservation of energy is a different principle and does not directly relate to the total amount of matter in a chemical reaction.

5. Which element is a good conductor of electricity but is not a metal?

• A. Copper
• B. Silver
• C. Graphite
• D. Gold

Correct answer: C

Rationale: The correct answer is graphite. Graphite is a non-metal that is a good conductor of electricity due to its unique electronic structure. While metals are typically known for their conductivity, graphite is an exception to this rule. Copper (choice A), silver (choice B), and gold (choice D) are all metals and are known for their excellent conductivity. Therefore, they do not fit the criteria of the question, which specifically asks for an element that is a good conductor of electricity but is not a metal.

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