Nursing Elites

1. The phenomenon responsible for the creation of rainbows is:

• A. Reflection only
• B. Diffraction
• C. Refraction and reflection
• D. Polarization

Correct answer: C

Rationale: The correct answer is C: Refraction and reflection. Rainbows are formed when sunlight is refracted and reflected inside raindrops. The sunlight entering the raindrop is refracted, then internally reflected off the back surface of the droplet, and finally refracted again as it exits the droplet. This dispersion of light causes the separation of colors we see in a rainbow. Reflection alone (option A) does not account for the formation of rainbows. Diffraction (option B) is the bending of light around obstacles, not the main mechanism behind rainbows. Polarization (option D) refers to the orientation of light waves, which is not the primary process involved in creating rainbows.

2. What is the term for the time it takes for a wave to complete one full cycle?

• A. Frequency
• B. Amplitude
• C. Period
• D. Wavelength

Correct answer: c

Rationale: The period of a wave is the time taken for one complete oscillation or cycle.

3. The Becquerel (Bq) is the designated unit for quantifying:

• A. Electron volt (eV) measurements of energy
• B. Radioactivity
• C. Electric charge (Coulombs)
• D. Force (Newtons)

Correct answer: B

Rationale: The Becquerel (Bq) is the designated unit for quantifying radioactivity. Radioactivity is the measure of the rate at which radioactive atoms undergo nuclear decay and emit radiation. One Becquerel is equal to one nuclear decay event per second. This unit is named after Henri Becquerel, the scientist who discovered radioactivity. Therefore, option B, 'Radioactivity,' is the correct answer. Electron volt (eV) measurements of energy are quantified using a different unit, electric charge is measured in Coulombs, and force is quantified in Newtons, making them incorrect choices for this question.

4. Which sentence uses the past perfect tense correctly?

• A. By the time I arrived, the party had already begun.
• B. I wish I had studied harder for the exam.
• C. We will have finished the project by Monday.
• D. She had been waiting for hours before he finally showed up.

Correct answer: A

Rationale: Option A expresses an action ("party began") completed before another past action ("I arrived").

5. A person pushes a box across a floor with a constant force. The box eventually comes to a stop due to friction. What happens to the work done by the person?

• A. It increases as the box moves further.
• B. It decreases as the box slows down.
• C. It remains constant throughout the motion.
• D. It becomes zero once the box stops.

Correct answer: C

Rationale: Work is defined as force multiplied by distance, and as long as the force remains constant, the work done increases proportionally to the distance moved, even if the box slows down due to friction.

6. The critical angle is defined as the minimum angle of incidence in a denser medium for which light undergoes:

• A. Total internal reflection
• B. Continued refraction
• C. Specular reflection
• D. Increased dispersion

Correct answer: A

Rationale: The critical angle is the minimum angle of incidence at which light is totally internally reflected rather than refracted. When light travels from a denser medium to a rarer medium at an angle greater than the critical angle, it undergoes total internal reflection. This phenomenon is crucial in applications like fiber optics and mirages. Continued refraction (option B) occurs when light enters a medium at an angle less than the critical angle. Specular reflection (option C) refers to the reflection of light at a smooth surface. Increased dispersion (option D) involves the separation of light into its constituent colors due to varying refractive indices, which is not directly related to the critical angle. Therefore, the correct answer is A - total internal reflection.

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