Medical Tests Medical Tests Certifications MCAT-TEST Questions & Answers

• Question 141:

  The pages of the look are visible to us because they:

  A. absorb light.

  B. emit light.

  C. reflect light.

  D. refract light.

  Correct Answer: C

• Question 142:

  If a person throws a stone vertically upwards while sitting in a train moving with constant velocity, the stone will fall:

  A. in his hand.

  B. behind him.

  C. in front of him.

  D. outside the train.

  Correct Answer: A

• Question 143:

  A neutral body is rubbed and its charge becomes positive. It must have:

  A. gained protons.

  B. gained neutrons.

  C. gained electrons.

  D. lost electrons.

  Correct Answer: C

• Question 144:

  Angular momentum is defined as:

  A. the dot product of position vector and linear momentum.

  B. the cross product of position vector and linear momentum.

  C. the simple product of position vector and linear momentum.

  D. the product of distance and linear momentum.

  Correct Answer: B

• Question 145:

  A charged particle is placed in an electrical field E. If the charge on the particle is doubled, the force exerted on the particle by the field is:

  A. doubled.

  B. halved.

  C. quadrupled.

  D. unchanged.

  Correct Answer: A

• Question 146:

  What is the wavelength of the light in millimeter?

  A. 5.4 x 10-3

  B. 5.4 x 10-5

  C. 5.4 x 10-4

  D. 5.4 x 10-10

  Correct Answer: C

• Question 147:

  Elephants have large flat feet. It helps them, having heavy weight, in walking properly on ground and maintaining proper body posture by:

  A. reducing ground friction on their feet.

  B. reducing their pressure on ground.

  C. increasing feet penetration into ground.

  D. none of the above.

  Correct Answer: B

• Question 148:

  The second law of thermodynamic states that:

  A. 100% conversion of mechanical work into heat is not possible.

  B. 100% efficient heat engine is not possible.

  C. 100% conversion of heat into mechanical work is not possible.

  D. None of these.

  Correct Answer: C

• Question 149:

  The change in temperature of "20oC" is equivalent to change in temperature on Kelvin scale of:

  A. 0.9 K

  B. 20 K

  C. 11 K

  D. 6.7 K

  Correct Answer: B

• Question 150:

  The Earth's atmosphere reaches hundreds of kilometers above the surface of the planet. The lowest layer, the troposphere, extends from the ground to a height of approximately 12 km. Air pressure within the troposphere decreases with height above the ground, accompanied by a parallel trend in air density. The decrease in density has important consequences for the dissipation of air pollution from industrial smoke stacks. The gas from the stack is typically hotter and less dense than the surrounding air and rises. As a parcel of hot air rises, it expands approximately adiabatically doing work on the surrounding air. This results in a decrease in both its temperature and its density.

  

  Figure 1 A smoke stack functions to expel gaseous waste products from a chemical process. It is also an important means of removing heat from a reaction mixture. The heat corresponding to a change in temperature of a gas at constant pressure is

  

  

  given by , where is the heat added to the gas, n is the number of moles of gas, is the molar heat capacity of a particular gas at constant pressure, and T is the change in temperature. At atmospheric pressure, the

  

  molar heat capacity for steam, O (g) is approximately four times that of air.

  

  At constant pressure, the ratio between the volume expansion of a mole of gas with a high to that of a mole of gas with a low for a given heat input will be:

  A. greater than 1.

  B. less than 1.

  C. equal to 1.

  D. cannot be determined.

  Correct Answer: B

  

  The passage provides the equation . A gas with a high Cp will have a smaller change in temperature for a given Q than a gas with a low Cp. Change in temperature is directly proportional to change in volume (at constant pressure). Charles' Law describes this relationship:

  

  Thus, the gas with the high Cp will expand less than a gas with a low Cp and the ratio of this expansion will be less than 1.