Nursing Elites

1. Which of the following materials has the lowest density?

• A. Water
• B. Cork
• C. Aluminum
• D. Steel

Correct answer: B

Rationale: Cork has the lowest density among the given options. Cork is a lightweight material derived from the bark of cork oak trees and is known for its low density, making it float on water. Water, aluminum, and steel have higher densities compared to cork. Water is denser than cork because it has a consistent density of 1 g/cm³. Aluminum and steel are metals with much higher densities due to their atomic structures, making them denser than cork.

2. Why does potential energy increase as particles approach each other?

• A. Attractive forces increase.
• B. Attractive forces decrease.
• C. Repulsive forces increase.
• D. Repulsive forces decrease.

Correct answer: C

Rationale: The correct answer is C: Repulsive forces increase. As particles approach each other, the distance between them decreases, causing the repulsive forces between the particles to increase. This increase in repulsive forces leads to an increase in potential energy as the particles resist being pushed closer together. Choices A and B are incorrect because attractive forces do not increase or decrease in this scenario. Choice D is incorrect because repulsive forces actually increase as particles get closer, leading to a rise in potential energy.

3. Given the four wires described here, which would you expect to have the greatest resistance?

• A. 1 km of American wire gauge 1; diameter 7.35 mm
• B. 1 km of American wire gauge 2; diameter 6.54 mm
• C. 1 km of American wire gauge 3; diameter 5.83 mm
• D. 1 km of American wire gauge 4; diameter 5.19 mm

Correct answer: D

Rationale: The wire with the greatest resistance is the one with the smallest diameter, as resistance is inversely proportional to cross-sectional area. Gauge 4 with a 5.19 mm diameter has the smallest diameter and, therefore, the greatest resistance. Choice A, B, and C have larger diameters compared to choice D, so they would have lower resistance values.

4. Why doesn’t a raindrop accelerate as it approaches the ground?

• A. Gravity pulls it down at a constant rate.
• B. Air resistance counteracts the gravitational force.
• C. Its mass decreases, decreasing its speed.
• D. Objects in motion decelerate over distance.

Correct answer: B

Rationale: The correct answer is B. As a raindrop falls, it experiences air resistance which counteracts the gravitational force pulling it down. This balancing of forces prevents the raindrop from accelerating further as it approaches the ground. Choice A is incorrect because while gravity is pulling the raindrop down, air resistance opposes this force. Choice C is incorrect as the mass of the raindrop remains constant during its fall. Choice D is incorrect because objects in motion may decelerate due to various factors, but in this case, the focus is on why the raindrop doesn't accelerate.

5. What is the electric field inside a hollow conductor with a net charge?

• A. Remains constant
• B. Decreases
• C. Zero
• D. Becomes unpredictable

Correct answer: C

Rationale: The correct answer is C: Zero. According to Gauss’s Law, the electric field inside a hollow conductor (a conductor with no charge inside but a net charge on its surface) is zero. The charges reside on the outer surface of the conductor, causing the electric field inside to cancel out. Choices A, B, and D are incorrect because the electric field inside a hollow conductor with a net charge is not constant, does not decrease, and does not become unpredictable; it is zero due to the distribution of charges on its surface.

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