Nursing Elites

1. What is the primary function of hair on the human body?

• A. Insulation
• B. Sensory perception
• C. Protection
• D. Vitamin D synthesis

Correct answer: C

Rationale: The primary function of hair on the human body is protection. Hair acts as a barrier to protect the skin from external factors such as sunlight, dust, and other environmental elements. While hair can also provide some insulation by trapping heat near the body and contribute to sensory perception by detecting touch or movements, its main role is to safeguard the skin from potential harm, making protection the most essential function. Vitamin D synthesis is primarily related to the skin's exposure to sunlight and is not a direct function of hair.

2. What phenomenon occurs when a wave encounters a change in medium causing a change in its speed and direction?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Interference

Correct answer: A

Rationale: Refraction is the phenomenon that occurs when a wave encounters a change in medium, causing a change in its speed and direction. This change in speed and direction is due to the wave bending as it passes from one medium to another with a different density. It is essential to understand refraction as it plays a crucial role in various phenomena, such as the bending of light in lenses, the formation of rainbows, and the way seismic waves travel through the Earth's layers. Reflection, while also a wave phenomenon, involves the bouncing back of a wave when it encounters a boundary. Diffraction refers to the bending of waves around obstacles or through openings, and interference involves the combination of two or more waves to form a new wave pattern.

3. 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.

4. 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.

5. Which concentration unit depends on pressure?

• A. ppm
• B. ppb
• C. molarity
• D. molarity, ppb, and ppm

Correct answer: C

Rationale: The correct answer is 'C: molarity.' Molarity is the concentration unit that depends on pressure. In molarity, the concentration of a solution is expressed as the number of moles of solute per liter of solution. This means that changes in pressure can affect the volume of the solution and consequently the concentration. Choices A and B, ppm (parts per million) and ppb (parts per billion), respectively, are independent of pressure variations as they are based on mass ratios. Therefore, molarity is the only concentration unit listed that is directly influenced by changes in pressure.

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