Nursing Elites

1. A 10 kg box rests on a frictionless surface. A horizontal force of 20 N is applied to the box. What is the box's acceleration?

• A. 0.5 m/s²
• B. 1 m/s²
• C. 2 m/s²
• D. 10 m/s²

Correct answer: B

Rationale: The acceleration of an object is given by the formula \(a = \frac{F}{m}\), where \(F\) is the net force acting on the object and \(m\) is the mass of the object. In this case, the net force acting on the box is 20 N, and the mass of the box is 10 kg. Plugging these values into the formula, we get \(a = \frac{20}{10} = 2\) m/s².

2. In the context of optical fibers, chromatic dispersion refers to:

• A. The total internal reflection of light
• B. The spreading of light pulses due to different colors traveling at slightly different speeds
• C. The bending of light at the fiber core-cladding interface
• D. The absorption of light by the fiber material

Correct answer: B

Rationale: Chromatic dispersion in optical fibers refers to the spreading of light pulses due to different colors (wavelengths) traveling at slightly different speeds. This phenomenon can cause the different components of a light pulse to arrive at the receiver at slightly different times, leading to signal distortion. Choice A is incorrect because total internal reflection refers to the phenomenon where light is reflected back into the medium it originated from when hitting the boundary at an angle greater than the critical angle. Choice C is incorrect as it describes the principle of light being guided within an optical fiber through total internal reflection at the core-cladding interface. Choice D is incorrect as the absorption of light by the fiber material does not relate to chromatic dispersion.

3. What property of a wave represents the distance between two successive identical points on a wave?

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

Correct answer: A

Rationale: The wavelength of a wave represents the distance between two successive identical points on a wave, such as two crests or two troughs. It is typically measured in meters and is a fundamental characteristic of a wave, influencing its properties and behavior. Wavelength is crucial in wave physics, affecting phenomena like interference, diffraction, and the wave's speed in a medium. Amplitude refers to the maximum displacement of a wave from its rest position, frequency is the number of complete oscillations a wave makes in a given time, and period is the time it takes for a wave to complete one full cycle. These properties are different from wavelength and serve distinct purposes in describing waves.

4. What is the 'lock-and-key' model?

• A. Protein folding
• B. Enzyme-substrate interaction
• C. Muscle contraction
• D. Blood clotting

Correct answer: B

Rationale: The 'lock-and-key' model describes the specificity of the interaction between enzymes and their substrates. In this model, the enzyme's active site acts like a lock that can only be opened by the specific substrate molecule, which serves as the key. This specific binding ensures that enzymes catalyze particular reactions and do not interact with other molecules indiscriminately. Protein folding (option A) is the process by which a protein attains its functional three-dimensional structure but is not directly related to the lock-and-key model. Muscle contraction (option C) and blood clotting (option D) are complex biological processes but are not directly associated with the lock-and-key model of enzyme-substrate interaction.

5. What is the functional group present in amines?

• A. Hydroxyl
• B. Carbonyl
• C. Amine
• D. Nitro

Correct answer: C

Rationale: The functional group present in amines is the amine group, represented as -NH2. Amines are organic compounds characterized by the presence of a nitrogen atom bonded to hydrogen atoms. The amine group distinguishes amines from other types of organic compounds, such as alcohols with the hydroxyl group, ketones with the carbonyl group, and nitro compounds with the nitro group. Therefore, the correct answer is 'C: Amine.'

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