Nursing Elites

1. In the context of the cardiac cycle, the P wave on an electrocardiogram (ECG) represents:

• A. Atrial depolarization
• B. Ventricular depolarization
• C. Atrial repolarization
• D. Ventricular repolarization

Correct answer: A

Rationale: The correct answer is A: "Atrial depolarization." The P wave on an ECG represents the depolarization of the atria, specifically the spread of electrical activity through the atria causing them to contract and push blood into the ventricles. This is the first wave observed on the ECG and signifies the beginning of the cardiac cycle. Ventricular depolarization is represented by the QRS complex, atrial repolarization is typically not visible on a standard ECG due to its timing with the QRS complex, and ventricular repolarization is represented by the T wave. Therefore, option A is the most appropriate choice in this context.

2. Which term describes the ability of a substance to conduct electricity?

• A. Reactivity
• B. Density
• C. Conductivity
• D. Viscosity

Correct answer: c

Rationale: Conductivity refers to a substance's ability to conduct electricity. Substances that conduct electricity well are known as conductors.

3. What type of lens is thinner at the center than at the edges and causes light rays to diverge?

• A. Convex lens
• B. Concave lens
• C. Diverging lens
• D. Plano-convex lens

Correct answer: b

Rationale: A concave lens is thinner at the center than at the edges and diverges light rays.

4. Peppered moths in England came in two color variations – light and dark. After the Industrial Revolution, the population shifted towards more dark moths. This is an example of:

• A. Artificial selection (humans breeding for desired traits)
• B. Natural selection acting on pre-existing variation
• C. Punctuated equilibrium (rapid bursts of evolution)
• D. Lamarckism (inheritance of acquired characteristics)

Correct answer: B

Rationale: Rationale: The phenomenon of peppered moths in England shifting towards more dark moths after the Industrial Revolution is a classic example of natural selection acting on pre-existing variation. Before the Industrial Revolution, light-colored moths were better camouflaged against lichen-covered tree trunks, which were common in the environment. However, with the increase in industrial pollution, the tree trunks became darker due to soot, making dark-colored moths better camouflaged and less likely to be eaten by predators. As a result, the population shifted towards more dark moths over time. This change in the moth population was driven by the selective pressure of predation, demonstrating the process of natural selection favoring individuals with traits that provide a survival advantage in a changing environment.

5. In physics, what term describes the resistance of an object to changes in its motion?

• A. Inertia
• B. Momentum
• C. Gravity
• D. Kinetic energy

Correct answer: A

Rationale: Inertia is the term that describes the resistance of an object to changes in its motion. This property is described by Newton's First Law of Motion, which states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force. Momentum (B) is the product of an object's mass and velocity, gravity (C) is the force that attracts objects towards each other, and kinetic energy (D) is the energy an object possesses due to its motion.

6. What happens to the work done on an object when the angle between force and displacement is 90 degrees?

• A. Maximum work is done
• B. No work is done
• C. Minimum work is done
• D. Work is infinite

Correct answer: b

Rationale: When the angle between force and displacement is 90 degrees, the work done on the object is zero.

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