Nursing Elites

1. Which substance would be most affected by a change in temperature?

• A. Liquid nitrogen
• B. Salt crystals
• C. Hydrogen gas
• D. Iron filings

Correct answer: C

Rationale: Hydrogen gas would be most affected by a change in temperature because gases have a greater expansion or contraction in volume with changes in temperature compared to liquids or solids. When the temperature of hydrogen gas increases, its molecules gain kinetic energy and move faster, causing the gas to expand and its volume to increase. Conversely, when the temperature decreases, the gas molecules lose kinetic energy and move slower, leading to a decrease in volume. This property makes hydrogen gas highly sensitive to temperature changes compared to liquid nitrogen, salt crystals, or iron filings. Liquid nitrogen, salt crystals, and iron filings are less affected by temperature changes because their particles are closer together and have lower kinetic energy, resulting in minimal volume changes with temperature fluctuations.

2. Faraday's law of electromagnetic induction states that a changing magnetic field in a conductor induces a/an:

• A. Increase in resistance
• B. Electromotive force
• C. Static electric charge
• D. Decrease in capacitance

Correct answer: B

Rationale: Faraday's law of electromagnetic induction states that a changing magnetic field induces an electromotive force in a conductor. This electromotive force is responsible for generating electricity in power plants and various electrical devices. The induced current is a result of the changing magnetic field, not an increase in resistance (choice A), static electric charge (choice C), or a decrease in capacitance (choice D). Hence, the correct answer is B.

3. What is the diameter of a loop if its radius is 6 meters?

• A. 6 m
• B. 12 m
• C. 18 m
• D. 36 m

Correct answer: B

Rationale: The diameter of a loop is calculated by multiplying the radius by 2. Since the radius is 6 meters, the diameter is 6 × 2 = 12 meters. Therefore, the correct answer is 12 meters. Choice A (6 m) is the radius, not the diameter. Choices C (18 m) and D (36 m) are incorrect as they do not reflect the correct calculation for determining the diameter of a loop.

4. The specific heat capacity of water is about 2 J/g°C. How much energy would you need to heat 1 kilogram of water by 10°C?

• A. 420 J
• B. 4,200 J
• C. 42,000 J
• D. 420,000 J

Correct answer: C

Rationale: The formula to calculate the energy required to heat a substance is Q = m × c × ΔT, where m is the mass, c is the specific heat capacity, and ΔT is the change in temperature. Given that 1 kilogram of water is equal to 1,000 grams, the mass (m) is 1,000 g, the specific heat capacity (c) of water is 4.2 J/g°C (not 2 J/g°C), and the change in temperature (ΔT) is 10°C. Substituting these values into the formula: Q = 1,000 × 4.2 × 10 = 42,000 J. Therefore, the correct energy required to heat 1 kilogram of water by 10°C is 42,000 J. Choices A, B, and D are incorrect as they do not consider the correct specific heat capacity of water or the conversion of mass to grams.

5. An object with a charge of 4 μC is placed 1 meter from another object with a charge of 2 μC. What is the magnitude of the resulting force between the objects?

• A. 0.04 N
• B. 0.072 N
• C. 80 N
• D. 8 × 10−6 N

Correct answer: A

Rationale: To find the magnitude of the resulting force between two charges, we can use Coulomb's law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. The formula for Coulomb's law is: F = k × (|q1 × q2| / r²), where F is the force, k is the Coulomb constant, q1 and q2 are the charges, and r is the distance between the charges. Substituting the given values into the formula: F = (9 × 10⁹ N·m²/C²) × ((4 × 10⁻⁶ C) × (2 × 10⁻⁶ C) / (1 m)²) = 0.04 N. Therefore, the magnitude of the resulting force between the objects is 0.04 N.

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