Nursing Elites

1. The unit for measuring luminous flux, which describes the perceived brightness of a light source by the human eye, is:

• A. Candela
• B. Lumen
• C. Lux
• D. Hertz

Correct answer: A

Rationale: The correct answer is B: Lumen. Luminous flux is the measure of the total quantity of visible light emitted by a source per unit time, measured in lumens. The candela (A) is the unit for luminous intensity, lux (C) is the unit for illuminance (luminous flux per unit area), and Hertz (D) is the unit for frequency. Therefore, in this question, the unit for measuring luminous flux is the lumen, as it specifically quantifies the perceived brightness of a light source by the human eye.

2. According to the wave theory of light, the bright fringes observed in a double-slit experiment correspond to:

• A. Constructive interference
• B. Destructive interference
• C. Increased diffraction
• D. Total internal reflection

Correct answer: A

Rationale: The correct answer is A: Constructive interference. According to the wave theory of light, when two light waves meet in phase (crest to crest or trough to trough), they combine to produce a brighter fringe. This is known as constructive interference, leading to the formation of bright fringes in a double-slit experiment. Destructive interference, on the other hand, occurs when two waves are out of phase (crest to trough), resulting in a dimmer or dark fringe. Increased diffraction refers to the bending of light waves around obstacles, not the formation of bright fringes. Total internal reflection is a phenomenon that occurs at the boundary between two different mediums when light is reflected back into the original medium. Therefore, the bright fringes observed in a double-slit experiment correspond to constructive interference.

3. he shimmering image of water seen on a hot road is a well-known example of:

• A. Reflection
• B. Refraction
• C. Interference
• D. Polarization

Correct answer: B

Rationale: The shimmering image of water seen on a hot road is a classic example of refraction. Refraction occurs when light waves pass from one medium to another, causing them to change direction due to the change in speed. In this scenario, the air above the road is hotter than the air closer to the ground, creating different densities of air which causes light to bend and distort, giving the illusion of water. Reflection, on the other hand, is the bouncing back of light waves from a surface, interference involves the superposition of two or more waves, and polarization is the orientation of light waves in a specific direction. Therefore, option B, refraction, is the correct answer in this case.

4. What is the difference between type 1 and type 2 diabetes, both related to insulin and blood sugar?

• A. Type 1 is caused by insulin resistance, type 2 by insulin deficiency.
• B. Type 1 is temporary, type 2 is permanent.
• C. Type 1 affects adults, type 2 affects children
• D. Type 1 is treated with diet only, type 2 requires medication.

Correct answer: A

Rationale: The correct answer is A: 'Type 1 is caused by insulin resistance, type 2 by insulin deficiency.' Type 1 diabetes is an autoimmune condition where the body attacks insulin-producing cells, leading to insulin deficiency. In contrast, type 2 diabetes occurs when the body becomes resistant to insulin's effects. This distinction is crucial for understanding the underlying causes and treatment approaches for each type of diabetes. Type 1 diabetes is not temporary; it is a chronic condition that requires lifelong management. Type 2 diabetes can also affect adults, but it is more commonly diagnosed in middle-aged and older adults. Treatment for type 1 diabetes typically involves insulin therapy along with diet and exercise, while type 2 diabetes may require medication in addition to lifestyle modifications.

5. What is the scientific term for a muscle that helps another muscle perform its action?

• A. Agonist
• B. Antagonist
• C. Synergist
• D. Fixator

Correct answer: C

Rationale: The correct answer is C: Synergist. A synergist muscle is a muscle that assists the prime mover (agonist) in performing its action by stabilizing joints or contributing extra force to the movement. Antagonist muscles oppose the action of the prime mover, while fixator muscles stabilize the origin of the prime mover to allow efficient movement. Understanding the roles of these muscles is essential in comprehending how various muscle groups work together to produce coordinated movements.

6. In which direction do the particles of the medium move in a transverse wave?

• A. Perpendicular to the direction of wave travel
• B. Parallel to the direction of wave travel
• C. In a circular motion
• D. Opposite to the direction of wave travel

Correct answer: a

Rationale: In a transverse wave, particle displacement occurs perpendicular to the direction of wave travel.

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