Nursing Elites

1. A convex lens is characterized by its ability to:

• A. Converge light rays
• B. Diverge light rays
• C. Focus sound waves
• D. Create virtual images only

Correct answer: A

Rationale: The correct answer is A: 'Converge light rays.' A convex lens is thicker in the center and thinner at the edges, causing light rays passing through it to converge or come together at a focal point. This ability is what enables convex lenses to bend light rays inward, focusing them to produce clear images. Options B and C are incorrect because convex lenses do not diverge light rays or focus sound waves. Option D is also incorrect as convex lenses can create both real and virtual images based on the position of the object with respect to the lens. Therefore, the main characteristic of a convex lens is its ability to converge light rays to form focused images.

2. What property of a substance remains constant regardless of changes in gravity?

• A. Mass
• B. Weight
• C. Volume
• D. Density

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. Weight, on the other hand, is a measure of the gravitational force acting on an object and varies with changes in gravity. Volume is the amount of space occupied by an object and can change with changes in gravity. Density is the mass of a substance per unit volume and can also change with changes in gravity if the volume changes.

3. The muscular diaphragm plays a vital role in respiration. When it contracts, it:

• A. Increases lung volume for inhalation
• B. Decreases lung volume for exhalation
• C. Filters dust and particles from inhaled air
• D. Produces mucus to lubricate the airways

Correct answer: A

Rationale: The diaphragm is a crucial muscle involved in respiration. When the diaphragm contracts, it flattens and moves downwards, increasing the volume in the thoracic cavity. This expansion creates a negative pressure in the lungs, causing air to rush in during inhalation. Therefore, option A, 'Increases lung volume for inhalation,' is the correct answer. The diaphragm's contraction facilitates the breathing process by creating space for the lungs to expand and take in air, making it essential for proper respiration.

4. Which sexually transmitted infection (STI) can potentially cause infertility in both men and women if left untreated?

• A. Human papillomavirus (HPV)
• B. Chlamydia
• C. Gonorrhea
• D. Syphilis

Correct answer: D

Rationale: The correct answer is D: Syphilis. Syphilis is a sexually transmitted infection that can potentially cause infertility in both men and women if left untreated. In men, untreated syphilis can lead to damage to the testicles and epididymis, affecting sperm production. In women, syphilis can result in pelvic inflammatory disease (PID) which can lead to scarring and blockages in the fallopian tubes, causing infertility. While other STIs like chlamydia and gonorrhea can also lead to infertility if left untreated, syphilis is particularly known for its severe impact on reproductive health in both genders.

5. Antiparticles possess properties opposite to their corresponding particles. Which of the following is the antiparticle of a neutron?

• A. Antineutrino
• B. Positron
• C. Antiproton
• D. Electron

Correct answer: A

Rationale: The correct answer is A: Antineutrino. Antiparticles possess properties that are opposite to their corresponding particles. A neutron is a neutral subatomic particle found in the nucleus of an atom. Its antiparticle, the antineutrino, has opposite properties, such as having no electric charge compared to the neutron's neutral charge. A positron (B) is the antiparticle of an electron, an antiproton (C) is the antiparticle of a proton, and an electron (D) is not an antiparticle. Therefore, the antiparticle of a neutron is the antineutrino.

6. Which part of the heart generates the QRS complex on an ECG?

• A. Sinoatrial node (SA node)
• B. Atrioventricular node (AV node)
• C. Bundle of His
• D. Ventricular muscle cells

Correct answer: D

Rationale: The correct answer is D, ventricular muscle cells. The QRS complex on an ECG represents the depolarization of the ventricles. This electrical activity is generated by the spread of impulses through the bundle branches and Purkinje fibers to the ventricular muscle cells. The SA node (option A) is responsible for initiating the electrical impulse in the heart, but it does not directly generate the QRS complex. The AV node (option B) delays the impulse to allow for proper coordination of atrial and ventricular contractions. The Bundle of His (option C) and its branches facilitate the conduction of the electrical signal from the AV node to the ventricles but do not generate the QRS complex directly.

Similar Questions