Nursing Elites

1. What happens to the frequency of a wave when its wavelength is doubled, assuming the speed remains constant?

• A. Frequency remains the same.
• B. Frequency is halved.
• C. Frequency is doubled.
• D. Frequency information is insufficient to determine.

Correct answer: C

Rationale: Since the wave speed is constant, if the wavelength increases, the frequency must decrease to maintain the same energy transfer per unit time.

2. The human immunodeficiency virus (HIV) targets and destroys which type of immune cell?

• A. Neutrophils
• B. Macrophages
• C. Helper T cells
• D. Memory B cells

Correct answer: A

Rationale: The correct answer is C: Helper T cells. HIV targets and destroys Helper T cells, which are a crucial component of the immune system responsible for coordinating the immune response. Neutrophils and macrophages are also important immune cells, but they are not the primary target of HIV. Memory B cells are responsible for mounting a rapid response upon re-exposure to a pathogen but are not the main target of HIV. Thus, HIV primarily affects Helper T cells, leading to the weakening of the immune system and the development of acquired immunodeficiency syndrome (AIDS).

3. A concave mirror can be used to:

• A. Focus light to a single point
• B. Only create virtual images
• C. Always magnify objects
• D. Scatter light

Correct answer: A

Rationale: A concave mirror can be used to focus light to a single point because of its reflective surface that curves inward. When light rays parallel to the mirror's principal axis strike the mirror, they converge at a focal point, creating a real image. This property makes concave mirrors useful in applications like reflecting telescopes and headlights, where focusing light to a point is necessary for proper functioning. Virtual images are also created by concave mirrors, but the primary function is to focus light rather than create virtual images. Magnification of objects and scattering of light are not inherent properties of concave mirrors.

4. The lymphatic system is primarily responsible for:

• A. Transporting nutrients throughout the body
• B. Removing excess fluids and waste products from tissues
• C. Producing red blood cells
• D. Regulating body temperature

Correct answer: B

Rationale: The correct answer is B: 'Removing excess fluids and waste products from tissues.' The lymphatic system plays a crucial role in maintaining fluid balance in the body by collecting excess interstitial fluid and returning it to the bloodstream. This system also helps in removing waste products, pathogens, and toxins from tissues, contributing to the body's immune response. Options A, C, and D are incorrect because transporting nutrients, producing red blood cells, and regulating body temperature are primarily the functions of other systems in the body such as the circulatory system, bone marrow, and the thermoregulatory system, respectively.

5. What happens to the internal energy of a system when it performs work on its surroundings?

• A. It increases.
• B. It decreases.
• C. It remains the same.
• D. Information insufficient

Correct answer: B

Rationale: When a system performs work on its surroundings, it loses internal energy in accordance with the first law of thermodynamics.

6. A decorative box has a rectangular base (20cm by 15cm) and a hemispherical top with the same diameter as the base. What is the total surface area of the box (excluding the base)?

• A. 825 sq cm
• B. 1075 sq cm
• C. 1325 sq cm
• D. 1575 sq cm

Correct answer: C

Rationale: Calculate the surface area of the lateral sides and the hemisphere, then add them up.

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