Nursing Elites

1. In which units is the speed of light in a vacuum measured?

• A. Meters per second
• B. Hertz
• C. Candela
• D. Newton

Correct answer: A

Rationale: The speed of light in a vacuum is commonly measured in units of meters per second. This is because the speed of light is approximately 299,792,458 meters per second in a vacuum, as defined by the International System of Units (SI). The speed of light is a measure of distance covered by light in a given time, hence it is expressed in meters per second. Choices B, C, and D are incorrect. Hertz is a unit of frequency, Candela is a unit of luminous intensity, and Newton is a unit of force. None of these units are relevant for measuring the speed of light, making 'Meters per second' the correct unit of measurement for the speed of light.

2. What is the correct way to represent 8,600,000,000,000 in scientific notation with two significant figures?

• A. 8.6 x 10^12
• B. 8.6 x 10^-12
• C. 8.6 x 10^11
• D. 8.60 x 10^12

Correct answer: A

Rationale: The correct way to represent 8,600,000,000,000 in scientific notation with two significant figures is 8.6 x 10^12. Scientific notation involves expressing a number as a decimal (with one non-zero digit before the decimal point) multiplied by a power of 10. In this case, 8,600,000,000,000 is correctly written as 8.6 x 10^12 to maintain two significant figures and the appropriate magnitude. Choice B (8.6 x 10^-12) is incorrect as it represents a very small number due to the negative exponent. Choice C (8.6 x 10^11) is incorrect as it does not account for the magnitude of the original number. Choice D (8.60 x 10^12) is incorrect because it unnecessarily adds a zero after the decimal point, which is not warranted by the original number's precision.

3. What term describes the functional unit of a skeletal muscle responsible for muscle contraction?

• A. Myofibril
• B. Sarcomere
• C. Tendon
• D. Myoglobin

Correct answer: B

Rationale: The correct answer is B, 'Sarcomere.' The sarcomere is indeed the functional unit of a skeletal muscle responsible for muscle contraction. It is composed of actin and myosin filaments that interact to generate muscle contraction. Choice A, 'Myofibril,' is incorrect as myofibrils are composed of sarcomeres, not the functional units themselves. Choice C, 'Tendon,' is incorrect as tendons connect muscles to bones and do not directly participate in muscle contraction. Choice D, 'Myoglobin,' is incorrect as myoglobin is a protein that stores oxygen in muscle cells and is not directly involved in muscle contraction.

4. What property of matter determines its resistance to changes in shape or size?

• A. Solid
• B. Liquid
• C. Gas
• D. Plasma

Correct answer: A

Rationale: The correct answer is 'Solid.' Solids have a definite shape and volume, providing them with a strong resistance to changes in shape or size. Liquids and gases do not have a definite shape, making them prone to changing shape or size easily. Plasmas, on the other hand, are ionized gases with high energy levels and lack a definite shape or volume, which does not contribute to resistance against changes in shape or size. Therefore, the properties of solids make them best suited for resisting changes in shape or size compared to liquids, gases, and plasmas.

5. Which of the following is responsible for maintaining the body's circadian rhythm?

• A. Thyroid gland
• B. Pineal gland
• C. Pancreas
• D. Hypothalamus

Correct answer: B

Rationale: The pineal gland is responsible for maintaining the body's circadian rhythm by producing melatonin. Melatonin is a hormone that helps regulate the sleep-wake cycle and is essential in controlling the body's internal clock. The thyroid gland, although important for metabolism, is not directly involved in regulating circadian rhythms. The pancreas plays a role in blood sugar regulation through insulin production, not in controlling circadian rhythms. The hypothalamus is involved in regulating various bodily functions, but the pineal gland is specifically responsible for the circadian rhythm.

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