Nursing Elites

1. An incandescent lamp consumes 60 Joules of energy per second. What is the power rating of this lamp?

• A. 1 Watt (W)
• B. 60 Watts (W)
• C. 1/60 Joules
• D. Impossible to determine without knowing the voltage

Correct answer: B

Rationale: Power is defined as energy consumed per unit time. If the lamp consumes 60 Joules of energy per second, the power rating is 60 Watts. Therefore, choice B is correct. Choice A ('1 Watt') is incorrect because the lamp consumes 60 Joules per second, not 1 Joule per second. Choice C ('1/60 Joules') is incorrect as it does not represent the power rating. Choice D ('Impossible to determine without knowing the voltage') is incorrect because power can be calculated using energy consumption per unit time without needing to know the voltage.

2. Which of these substances is most compressible?

• A. Gold
• B. Water
• C. Mercury
• D. Methane

Correct answer: D

Rationale: Methane, a gas at room temperature and pressure, is the most compressible substance among the options provided. Gases are generally more compressible compared to liquids and solids because their particles have more space between them, allowing for greater compression when pressure is applied. Gold, water, and mercury, being solid and liquid substances, respectively, have particles arranged closely together, making them less compressible. Therefore, the correct answer is Methane.

3. What is the mathematical expression for work (W)?

• A. W = F / d
• B. W = F x d
• C. W = d / F
• D. W = F^2 x d

Correct answer: B

Rationale: The correct formula for work (W) is given by the equation W = F x d, where F represents force and d represents the displacement in the direction of the force. Work is calculated by multiplying the force applied by the distance over which the force is applied. Choice A (W = F / d) is incorrect as work is not calculated by dividing force by distance. Choice C (W = d / F) is incorrect because work is not calculated by dividing distance by force. Choice D (W = F^2 x d) is incorrect as work is not calculated by squaring the force and then multiplying by distance.

4. A Carnot cycle is a theoretical ideal heat engine operating between two heat reservoirs at different temperatures. Which of the following statements is NOT true about a Carnot cycle?

• A. The efficiency of a Carnot cycle is solely dependent on the absolute temperatures of the hot and cold reservoirs.
• B. It is a reversible cycle, meaning the process can be run in both directions with the same efficiency.
• C. It operates isothermally at the hot and cold reservoir temperatures.
• D. It is the most efficient heat engine operating between the same two reservoir temperatures.

Correct answer: C

Rationale: The statement that is NOT true is C. Although part of the Carnot cycle operates isothermally, not the entire cycle operates isothermally. The Carnot cycle consists of both isothermal and adiabatic processes. Choice A is incorrect because the efficiency of a Carnot cycle is indeed solely dependent on the absolute temperatures of the hot and cold reservoirs. Choice B is correct as a Carnot cycle is reversible, allowing the process to be run in both directions with the same efficiency. Choice D is also true as the Carnot cycle is the most efficient heat engine operating between the same two reservoir temperatures. Therefore, the correct answer is C.

5. An object with a charge of 4 μC is placed 50 cm from another object with a charge twice as great. What is the magnitude of the resulting repulsive force?

• A. 0.1152 N
• B. 1.152 N
• C. 10^−3 N
• D. 2.5 × 10^−3 N

Correct answer: D

Rationale: The force between two charges is calculated using Coulomb's Law, which states that the force is proportional to the product of the two charges and inversely proportional to the square of the distance between them. Given that one charge is twice as great as the other and the distance between them is 50 cm, we can calculate the repulsive force. The magnitude of the resulting repulsive force is 2.5 × 10^−3 N. Choice A is incorrect as it does not match the calculated value. Choice B is incorrect as it is significantly higher than the correct answer. Choice C is incorrect as it represents 10^−3 N, which is lower than the calculated value.

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