Nursing Elites

1. When a hot cup of coffee is placed on a cold table, heat transfer primarily occurs through which process?

• A. Radiation
• B. Conduction
• C. Convection within the coffee
• D. A combination of conduction and convection

Correct answer: B

Rationale: When a hot cup of coffee is placed on a cold table, heat transfer primarily occurs through conduction. Conduction is the process of heat transfer through direct contact between objects at different temperatures. In this scenario, the heat from the hot coffee cup is transferred to the cold table through direct contact, making conduction the primary mode of heat transfer. Choice A (Radiation) is incorrect because radiation is the transfer of heat through electromagnetic waves, which is not the primary mode of heat transfer in this scenario. Choice C (Convection within the coffee) is incorrect because convection is the transfer of heat through the movement of fluids, which is not the primary mode of heat transfer in this scenario. Choice D (A combination of conduction and convection) is incorrect because while convection may play a minor role due to air currents around the cup, the primary mode of heat transfer in this scenario is conduction.

2. Household alternating current typically has a frequency of 60 Hz. Which statement is true?

• A. The circuit is suitable for lighting 60-watt bulbs.
• B. Circuits in the home may carry a current of 60 amperes.
• C. The expected voltage drop is 60 volts per meter.
• D. Electrons complete a cycle 60 times per second.

Correct answer: D

Rationale: The correct answer is D. Electrons complete a cycle 60 times per second when the frequency of the current is 60 Hz. This frequency indicates that the current changes direction 60 times per second, causing the electrons to complete a full cycle back and forth through the circuit at the same rate. Choice A is incorrect because the power rating of a bulb (in watts) is not directly related to the frequency of the current. Choice B is incorrect as typical household circuits do not carry currents as high as 60 amperes. Choice C is incorrect as the expected voltage drop is not measured in volts per meter for household alternating current circuits.

3. 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.

4. Four 5 V batteries are connected in series. What is the total voltage of the circuit?

• A. 5.0 V
• B. 10.0 V
• C. 15.0 V
• D. 20.0 V

Correct answer: D

Rationale: When batteries are connected in series, their voltages add up. Therefore, the total voltage of the circuit with four 5 V batteries connected in series will be 5 V + 5 V + 5 V + 5 V = 20 V. Choices A, B, and C are incorrect because the voltages of the batteries add up in series, resulting in a total of 20 V.

5. What does Coulomb’s law relate to?

• A. electrostatic interaction
• B. rigid body motion
• C. heat conduction
• D. universal gravitation

Correct answer: A

Rationale: Coulomb's law is a fundamental principle in physics that deals with the electrostatic interaction between charged particles. It states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. This law is crucial in understanding and predicting the behavior of electrically charged objects. Choices B, C, and D are incorrect because Coulomb's law specifically focuses on electrostatic interactions between charges, not rigid body motion, heat conduction, or universal gravitation.

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