Nursing Elites

1. A solenoid is a long, tightly wound coil of wire that acts like a bar magnet when current flows through it. The magnetic field lines inside a solenoid are most similar to the field lines around:

• A. A single straight current-carrying wire
• B. A horseshoe magnet
• C. A permanent bar magnet
• D. A flat sheet conductor

Correct answer: C

Rationale: The magnetic field lines inside a solenoid resemble the field lines around a permanent bar magnet. Both a solenoid and a bar magnet have north and south poles, resulting in a similar pattern of magnetic field lines. A single straight current-carrying wire produces a different field pattern because it has no coil structure like a solenoid. A horseshoe magnet has a unique field shape due to its pole arrangement, different from the uniform field pattern of a solenoid. A flat sheet conductor does not exhibit the same magnetic field characteristics as a solenoid, as it lacks the coil shape and alignment of a solenoid's magnetic field.

2. An object has a constant velocity of 50 m/s and travels for 10 s. What is the acceleration of the object?

• A. 0 m/s²
• B. 5 m/s²
• C. 60 m/s²
• D. 500 m/s²

Correct answer: A

Rationale: The acceleration of an object is defined as the rate of change of its velocity. When an object has a constant velocity, it means there is no change in its speed or direction. In this case, the object maintains a constant velocity of 50 m/s for 10 seconds, which implies that there is no change in velocity. Therefore, the acceleration of the object is 0 m/s² as there is no acceleration or deceleration happening. Choices B, C, and D are incorrect because acceleration is the change in velocity over time, and in this scenario of constant velocity, the acceleration is 0 m/s².

3. Enthalpy (H) is a thermodynamic property defined as the sum of a system's internal energy (U) and the product of its pressure (P) and volume (V). The relationship between these is:

• A. H = U + PV
• B. H = U - PV
• C. H = U / PV
• D. H = PV / U

Correct answer: A

Rationale: Enthalpy (H) is defined as H = U + PV, where U represents internal energy, P is pressure, and V is volume. Enthalpy includes both the internal energy of a system and the energy required to create space for the system against an external pressure. Therefore, the correct relationship between enthalpy, internal energy, pressure, and volume is H = U + PV. Choice B is incorrect as subtracting PV would not account for the work done against pressure. Choice C is incorrect as dividing U by PV doesn't represent the definition of enthalpy. Choice D is incorrect as dividing PV by U is not the correct relationship based on the definition of enthalpy.

4. In the mechanical power equation P = E / t, power is measured in ___________.

• A. ohms
• B. Joules
• C. volts
• D. watts

Correct answer: D

Rationale: In the mechanical power equation P = E / t, power is measured in watts. Watts are the standard unit of power in the International System of Units (SI), named after the Scottish engineer James Watt. Watts are defined as joules per second, reflecting the rate at which energy is transferred or converted. Ohms (choice A) are the unit of electrical resistance, Joules (choice B) are the unit of energy, and volts (choice C) are the unit of electric potential difference. Therefore, the correct answer is watts as it directly relates to power in the given equation.

5. A 5-cm candle is placed 20 cm away from a concave mirror with a focal length of 10 cm. What is the image distance of the candle?

• A. 20 cm
• B. 40 cm
• C. 60 cm
• D. 75 cm

Correct answer: C

Rationale: To find the image distance of the candle, we use the mirror formula: 1/f = 1/do + 1/di, where f is the focal length, do is the object distance, and di is the image distance. In this case, the focal length f = 10 cm and the object distance do = 20 cm. Substituting these values into the formula gives us 1/10 = 1/20 + 1/di. Solving for di, we get di = 60 cm. Therefore, the image distance of the candle is 60 cm. Choice A (20 cm) is incorrect because it represents the object distance, not the image distance. Choice B (40 cm) is incorrect as it does not consider the mirror formula calculation. Choice D (75 cm) is incorrect as it does not match the correct calculation based on the mirror formula.

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