Medical College Admissions Test Latest Update

Medical College Admissions Test Latest Update - with Questions and Verified Correct Answers Golden Ticket to Guaranteed A+ Verified by Professor

Action potentials travel down neural axons that resist the flow of current. In considering a theoretical circuit, one normally assumes that the wire has no resistivity. In the real world, however, wire resistivity is an important consideration. Which of the following is a way to increase resistance?

• Lengthen the wire
• Widen the wire
• Lower the temperature

D) Change from tungsten to copper wire - CORRECT ANSWER: A

This question tests your knowledge of resistance in wires. An electrical wire's resistance is directly proportional to its length and inversely proportional to its cross-sectional area.Think of it as gravel in a pipe—the wider the pipe and the shorter the pipe, the easier it is for water to go through it.

B is incorrect because when a wire's cross-sectional area is increased, its resistivity is decreased.

C is incorrect because lowering temperature decreases resistivity. Think superconductors.

D is incorrect because tungsten has higher resistivity than copper. Tungsten is used for lightbulb filaments because of its higher resistivity.

Chemical extraction is a simple, but powerful, means of isolating a desired compound, and this technique is used to isolate many pharmacological agents. A chemist requires 1 / 2

that a mixture of two species be separated. In order to do this, the chemist allows the mixture to separate and extracts the top, non-polar layer. Based on this information, what is least likely to be true of the original two species?

• The densities of the species are different.
• The original species rotate plane-polarized light in opposite directions.
• The bottom layer is hydrophobic.

D) The two species have the same molecular weight. - CORRECT ANSWER: B

describes the species as enantiomers. If the two species can be separated through ordinary means, without first changing them chemically, they cannot be enantiomers!Enantiomers cannot be separated by physical properties alone.

Ideal gasses are useful for calculations, but perfectly "ideal" gasses do not exist in the real world. Under what conditions does a real gas differ in behavior from an ideal gas?

• increased pressure only
• increased temperature only
• increased pressure and decreased temperature

D) only when the molar volume is very large - CORRECT ANSWER: C

Real gases deviate from the ideal gas law due to elevated pressures and decreased temperatures. This is because as pressure increases, the molecules are forced closer together, so intermolecular interactions become important. When the molecules are far apart, the intermolecular forces are minimal. As temperature decreases, gas particles move more slowly, so as they pass each other, the period of time in which they are in close proximity increases. This allows more opportunities for the molecules to affect one another. Hence, deviations from ideal conditions result.

Most of the CO2 in the blood travels as HCO3- and H+ ions in the plasma. Which of the following would a physician most likely find upon examining a person who has recently had Acute Mountain Sickness (Altitude Sickness)?

• Increased levels of O2 in the plasma
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