Nursing Elites

1. What is the electric field inside a hollow conductor with a net charge?

• A. Remains constant
• B. Decreases
• C. Zero
• D. Becomes unpredictable

Correct answer: C

Rationale: The correct answer is C: Zero. According to Gauss’s Law, the electric field inside a hollow conductor (a conductor with no charge inside but a net charge on its surface) is zero. The charges reside on the outer surface of the conductor, causing the electric field inside to cancel out. Choices A, B, and D are incorrect because the electric field inside a hollow conductor with a net charge is not constant, does not decrease, and does not become unpredictable; it is zero due to the distribution of charges on its surface.

2. Fluid dynamics is a subfield of fluid mechanics concerned with:

• A. Equilibrium properties of fluids at rest (Fluid Statics)
• B. The motion and behavior of fluids under various conditions
• C. Phase transitions of fluids between liquid, gas, and solid states
• D. Engineering applications of fluids (related but broader than fluid dynamics)

Correct answer: B

Rationale: Fluid dynamics is the study of fluids in motion and their behavior under different conditions, including how they flow, mix, and interact with their surroundings. It focuses on the dynamic aspects of fluids rather than their static properties when at rest, which is the realm of fluid statics. Phase transitions of fluids between liquid, gas, and solid states are more related to thermodynamics than fluid dynamics. While engineering applications involve fluid dynamics, the field itself is more specialized in studying the movement and behavior of fluids.

3. Electric motors convert electrical energy primarily into:

• A. Thermal energy
• B. Light
• C. Mechanical energy
• D. Sound waves

Correct answer: C

Rationale: Electric motors convert electrical energy into mechanical energy. When electricity passes through the coils in the motor, it creates a magnetic field that interacts with the field from the permanent magnets, resulting in a force that drives motion. Choice A, 'Thermal energy,' is incorrect as electric motors are designed to minimize heat production. Choice B, 'Light,' is incorrect as electric motors do not produce light as a primary output. Choice D, 'Sound waves,' is incorrect as the primary output of an electric motor is mechanical motion, not sound waves.

4. What is the net force acting on the car?

• A. 450 N
• B. 700 N
• C. 1,500 N
• D. 6,300 N

Correct answer: C

Rationale: To determine the net force acting on an object, we need to consider the sum of the forces acting in the same direction and subtract the forces acting in the opposite direction. In this scenario, there is a force of 4,200 N to the right and a force of 2,700 N to the left. By subtracting the leftward force from the rightward force (4,200 N - 2,700 N), we find that the net force acting on the car is 1,500 N to the right. Therefore, choice C, 1,500 N, is the correct answer. Choice A, 450 N, is too small as it does not account for the total forces involved. Choice B, 700 N, is also incorrect as it is not the result of the correct mathematical operation on the given forces. Choice D, 6,300 N, is too large and does not align with the calculation based on the forces provided.

5. The speed of sound in dry air at 20°C is 343 m/s. If the wavelength of a sound wave is 5 m, what is its frequency?

• A. 171.5 Hz
• B. 79 Hz
• C. 68.6 Hz
• D. 63.6 Hz

Correct answer: C

Rationale: The speed of sound (v) can be calculated using the formula: v = f × λ, where f is the frequency and λ is the wavelength. Given that the speed of sound is 343 m/s and the wavelength is 5 m, we can rearrange the formula to solve for frequency: f = v / λ = 343 / 5 = 68.6 Hz. Therefore, the correct frequency is 68.6 Hz. Choices A, B, and D are incorrect as they do not result from the correct calculation based on the given values.

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