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. The specific heat capacity (c) of a material is the amount of heat transfer (Q) required to raise the temperature (ΔT) of a unit mass (m) of the material by one degree (typically Celsius). The relationship between these quantities is described by the equation:

• A. Q = cΔT
• B. Q = mcΔT
• C. Q = c / mΔT
• D. Q = ΔT / mc

Correct answer: A

Rationale: The correct equation relating heat transfer (Q), mass (m), specific heat capacity (c), and change in temperature (ΔT) is Q = mcΔT. This equation states that the heat transfer is equal to the product of the mass, specific heat capacity, and temperature change. Therefore, the correct answer is B, as it correctly represents this relationship. Choices C and D do not correctly represent the relationship between these quantities and are therefore incorrect.

3. A 780-watt refrigerator is powered by a 120-volt power source. What is the current being drawn?

• A. 660 amperes
• B. 150 amperes
• C. 6.5 amperes
• D. 0.15 amperes

Correct answer: C

Rationale: To calculate the current being drawn by the refrigerator, you can use the formula: Current (I) = Power (P) / Voltage (V). Given that the power of the refrigerator is 780 watts and the voltage is 120 volts, you can plug these values into the formula to find the current: I = 780 watts / 120 volts = 6.5 amperes. Therefore, the current being drawn by the 780-watt refrigerator is 6.5 amperes. Choice A, 660 amperes, is incorrect as it is significantly higher than the correct answer. Choice B, 150 amperes, is also incorrect and too high. Choice D, 0.15 amperes, is incorrect as it is too low. The correct answer is 6.5 amperes.

4. Energy manifests in various forms. Which of the following is NOT considered a fundamental energy type?

• A. Thermal energy
• B. Momentum
• C. Sound energy
• D. Chemical energy

Correct answer: B

Rationale: The correct answer is B. Momentum is not considered a form of energy; it is a property of moving objects. Thermal, sound, and chemical energy are all forms of energy. Thermal energy is the energy associated with the movement of particles within an object. Sound energy is produced by vibrations and travels through materials as waves. Chemical energy is stored within the bonds of chemical compounds. While momentum is a crucial concept in physics, it is not a fundamental form of energy.

5. In an electrically neutral atom, the number of:

• A. Electrons is equal to protons
• B. Protons is equal to neutrons
• C. Neutrons are always greater than protons
• D. Electrons are always less than protons

Correct answer: A

Rationale: In an electrically neutral atom, the number of electrons is equal to the number of protons. Electrons carry a negative charge, protons carry a positive charge, and neutrons are neutral. Since the atom is electrically neutral, the positive charge of the protons must balance the negative charge of the electrons, making the numbers of electrons and protons equal. Choice B is incorrect because protons are not equal to neutrons in an atom. Choice C is incorrect because neutrons are not always greater than protons, and choice D is incorrect because electrons are not always less than protons in an atom.

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