1. Muscle soreness after exercise is often caused by microscopic tears in muscle fibers. This is called

A. Atrophy
B. Hypertrophy
C. Dom (Delayed Onset Muscle Soreness)
D. Spasm

Correct answer: C

Rationale: Muscle soreness after exercise is commonly caused by microscopic tears in muscle fibers, leading to a condition known as Delayed Onset Muscle Soreness (DOMS). Atrophy refers to the shrinking of muscle due to inactivity or lack of use, which is not the cause of muscle soreness after exercise. Hypertrophy is the increase in muscle size through exercise, not related to muscle soreness. Spasm is a sudden, involuntary muscle contraction unrelated to the micro-tears that cause muscle soreness. Therefore, the correct answer is C, DOMS, as it specifically addresses the micro-tears in muscle fibers that result in post-exercise soreness.

2. The critical angle is defined as the minimum angle of incidence in a denser medium for which light undergoes:

A. Total internal reflection
B. Continued refraction
C. Specular reflection
D. Increased dispersion

Correct answer: A

Rationale: The critical angle is the minimum angle of incidence at which light is totally internally reflected rather than refracted. When light travels from a denser medium to a rarer medium at an angle greater than the critical angle, it undergoes total internal reflection. This phenomenon is crucial in applications like fiber optics and mirages. Continued refraction (option B) occurs when light enters a medium at an angle less than the critical angle. Specular reflection (option C) refers to the reflection of light at a smooth surface. Increased dispersion (option D) involves the separation of light into its constituent colors due to varying refractive indices, which is not directly related to the critical angle. Therefore, the correct answer is A - total internal reflection.

3. What is the difference between emphysema and chronic bronchitis, both chronic obstructive pulmonary diseases (COPD)?

A. Emphysema damages alveoli, while chronic bronchitis inflames airways.
B. Emphysema causes coughing, while chronic bronchitis leads to shortness of breath.
C. Emphysema is more reversible than chronic bronchitis.
D. Emphysema affects only smokers, while chronic bronchitis can occur in non-smokers.

Correct answer: A

Rationale: The correct answer is A. Emphysema and chronic bronchitis are both types of COPD, but they have distinct characteristics. Emphysema is characterized by the destruction of the alveoli in the lungs, which impairs the exchange of oxygen and carbon dioxide. This damage to the alveoli leads to difficulty breathing and decreased lung function. On the other hand, chronic bronchitis involves inflammation and narrowing of the airways, leading to excessive mucus production and a persistent cough. While both conditions are chronic and progressive, emphysema primarily affects the alveoli, while chronic bronchitis primarily affects the airways. Understanding these differences is crucial for appropriate diagnosis and management of COPD.

4. Which of the following is a balanced chemical equation?

A. H2 + O2 â†’ H2O
B. 2H2 + O2 â†’ 2H2O
C. 3H2O â†’ 2H2 + O2
D. H2O â†’ H2 + O2

Correct answer: b

Rationale: The equation is balanced, with equal numbers of atoms of each element on both sides.

5. Which of the following substances is an example of an acidic gas?

A. Nitrogen (Nâ‚‚)
B. Carbon dioxide (COâ‚‚)
C. Sulfur dioxide (SOâ‚‚)
D. Oxygen (Oâ‚‚)

Correct answer: C

Rationale: Sulfur dioxide is an acidic gas. The other choices are either neutral or basic gases.

6. The energy required to break a chemical bond is called:

A. Kinetic energy
B. Potential energy
C. Activation energy
D. Bond energy

Correct answer: C

Rationale: Rationale: Activation energy is the energy required to break a chemical bond and initiate a chemical reaction. Kinetic energy (option A) is the energy of motion, potential energy (option B) is stored energy, and bond energy (option D) is the energy required to break a particular chemical bond in a molecule. Among the options provided, activation energy best describes the energy required to break a chemical bond.