1.Amount of heat required to raise the temperature of 1 g of water from 14.5 to 15.5 degree centigrade is: 1. 1 Joule
2. 1 Calorie
3. 4.2 Calorie
4. none of the above

  4. none of the above

Explanation:

A "15 °C calorie" (with a lower-case 'c') is defined as the amount of energy required to raise 1 gram of water from 14.5 °C to 15.5 °C at standard atmospheric pressure. That definition is one of at least 7 different definitions of the "gram calorie".

A Calorie (with an upper-case 'C') is 1000 calories. So the choice "1 Calorie" is attractive, but incorrect. It is 1000 times the amount of heat described.

none of the Joule or Calorie choices is correct

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.