Nursing Elites

1. A light ray travels from air (refractive index 1.00) into water (refractive index 1.33). What happens to its speed and direction?

• A. Speed increases, direction bends towards the normal.
• B. Speed increases, direction bends away from the normal.
• C. Speed decreases, direction bends towards the normal.
• D. Speed and direction remain unchanged.

Correct answer: A

Rationale: Due to the change in refractive index, the light ray bends towards the normal (water) as it slows down upon entering the denser medium.

2. What type of waves require a medium (solid, liquid, or gas) to propagate?

• A. Transverse waves
• B. Longitudinal waves
• C. Electromagnetic waves
• D. Surface waves

Correct answer: B

Rationale: Longitudinal waves require a medium (solid, liquid, or gas) to propagate because the particles in the medium move parallel to the direction of the wave. Transverse waves, on the other hand, do not require a medium and can propagate through a vacuum. Electromagnetic waves also do not require a medium for propagation, as they consist of oscillating electric and magnetic fields. Surface waves are a combination of both longitudinal and transverse waves and also require a medium to propagate.

3. During exercise, oxygen is used to convert glucose into energy for muscles. This process is called:

• A. Aerobic respiration
• B. Anaerobic respiration
• C. Glycolysis
• D. Lactic acid fermentation

Correct answer: A

Rationale: The correct answer is 'A: Aerobic respiration.' During exercise, muscles require energy to function, and oxygen plays a crucial role in converting glucose into energy through aerobic respiration. This process occurs in the mitochondria of cells and involves the breakdown of glucose to produce ATP, the cell's energy currency. Aerobic respiration is efficient and produces a higher yield of ATP compared to anaerobic respiration or glycolysis alone. Anaerobic respiration (option B) and glycolysis (option C) are also involved in energy production but do not rely on oxygen. Lactic acid fermentation (option D) occurs when there is not enough oxygen available, leading to the accumulation of lactic acid. Therefore, the most appropriate answer is 'A: Aerobic respiration.'

4. Identify the spectator ions in the reaction: 2KCl + Pb(NO3)2 → 2KNO3 + PbCl2.

• A. K+ and NO3-
• B. K+ and Cl-
• C. Pb2+ and NO3-
• D. Pb2+ and Cl-

Correct answer: B

Rationale: Rationale: - In the reaction, potassium ions (K+) and chloride ions (Cl-) are present on both sides of the equation. They are not involved in the formation of the products and remain unchanged. - Lead ions (Pb2+) and nitrate ions (NO3-) are involved in the formation of the products potassium nitrate (KNO3) and lead(II) chloride (PbCl2). - Therefore, the spectator ions in this reaction are K+ and Cl-.

5. Which hormone, produced by the adrenal glands, prepares the body for a "fight or flight" response by increasing heart rate, dilating airways, and mobilizing energy stores?

• A. Cortisol
• B. Aldosterone
• C. Epinephrine
• D. Insulin

Correct answer: c

Rationale: The correct answer is C: Epinephrine. Epinephrine, also known as adrenaline, is the hormone produced by the adrenal glands that prepares the body for a 'fight or flight' response. It increases heart rate to pump more blood to muscles, dilates airways to improve oxygen intake, and mobilizes energy stores to provide immediate fuel for physical activity. Cortisol is a hormone involved in stress response and metabolism regulation, but it does not directly trigger the rapid physiological changes associated with 'fight or flight.' Aldosterone regulates salt and water balance, while insulin regulates blood sugar levels, neither of which are directly involved in preparing the body for a rapid response to danger or stress.

6. What is the half-life of a radioactive isotope, and how does it relate to its decay rate?

• A. The time it takes for half of the initial sample to decay.
• B. The time it takes for all the sample to decay.
• C. The rate at which new isotopes are created.
• D. The energy released during decay.

Correct answer: A

Rationale: Half-life tells the time it takes for half of the original radioactive nuclei to decay, offering an indication of the decay rate.

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