Nursing Elites

1. During an isothermal (constant temperature) expansion, what is the work done by the gas on the surroundings?

• A. Positive and equal to the change in internal energy.
• B. Zero.
• C. Negative and equal to the change in internal energy.
• D. Positive and greater than the change in internal energy.

Correct answer: D

Rationale: In an isothermal expansion, the temperature remains constant, meaning there is no change in internal energy. However, the gas still does work on the surroundings as it expands, and this work is positive. Since internal energy does not change, the correct answer is D, 'Positive and greater than the change in internal energy.' Choice A is incorrect because the work done is not equal to the change in internal energy. Choice B is incorrect as work is done during the expansion. Choice C is incorrect since the work done is not negative during an isothermal expansion.

2. Which of the following is NOT a mode of heat transfer between a system and its surroundings?

• A. Conduction
• B. Convection
• C. Radiation
• D. Isothermalization

Correct answer: A

Rationale: Isothermalization is not a mode of heat transfer. The three main modes of heat transfer are conduction (through direct contact), convection (through fluid motion), and radiation (through electromagnetic waves). In this question, choice A, conduction, is not a mode of heat transfer between a system and its surroundings. Conduction refers to heat transfer through direct contact between particles, without the movement of the particles themselves. Therefore, A is the correct answer. Choices B, C, and D are incorrect as they represent valid modes of heat transfer.

3. How might the energy use of an appliance be expressed?

• A. Power = energy × time
• B. Time + energy = power
• C. Energy = power × time
• D. Energy/power = time

Correct answer: C

Rationale: The energy use of an appliance can be expressed using the formula Energy = Power × Time. In this formula, Energy represents the amount of electricity consumed by the appliance, Power indicates the rate at which the appliance uses electricity (measured in watts), and Time represents the duration for which the appliance is being used (measured in hours). By multiplying the power rating of the appliance by the time it is in use, one can calculate the total energy consumed. Option C is the correct choice because it accurately represents the relationship between power, time, and energy. Choices A, B, and D present incorrect representations of the relationship between energy, power, and time, making them wrong answers.

4. Two objects attract each other with a gravitational force of 12 units. If you double the distance between the objects, what is the new force of attraction between the two?

• A. 3 units
• B. 6 units
• C. 24 units
• D. 48 units

Correct answer: A

Rationale: The gravitational force between two objects is inversely proportional to the square of the distance between them. If the distance is doubled, the force will be reduced to 1/4 of the original force. Therefore, the new force of attraction between the two objects will be 12 units / 4 = 3 units. Choice A is correct because doubling the distance reduces the force to 1/4 of the original value. Choices B, C, and D are incorrect as they do not consider the inverse square relationship between distance and gravitational force.

5. A bicycle and a car are both traveling at a rate of 5 m/s. Which statement is true?

• A. The bicycle has more kinetic energy than the car.
• B. The bicycle has less kinetic energy than the car.
• C. Both vehicles have the same amount of kinetic energy.
• D. Only the car has kinetic energy.

Correct answer: B

Rationale: Kinetic energy is determined by both the mass and the velocity of an object. While both the bicycle and the car are moving at the same velocity (5 m/s), the car has significantly more mass than the bicycle. As a result, the car has more kinetic energy than the bicycle, even though their speeds are identical. Therefore, choice B is correct. Choices A, C, and D are incorrect because they do not consider the influence of mass on kinetic energy. Choice A is incorrect as the car has more kinetic energy due to its greater mass. Choice C is incorrect because the vehicles have different masses. Choice D is incorrect as both the bicycle and the car possess kinetic energy.

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