1. A mass of 20 kg falls 90m. If all its potential energy is converted to heat and gravitational acceleration = 9.8 m/s2, then the heat gained is   1800 J   196 J   882 J   17640 J   Hint Half-n-half Clue   2. The SI unit of heat (thermal energy) is   Pascal   Watt   Joule   Newton   Half-n-half Clue   3. The heat produced on burning 7 kg of fuel oil which has a calorific value of 39800 kJ/kg is   278.6 MJ   278600 MJ   5685.7 MJ   5.7 MJ   Half-n-half Clue   4. Heat is a form of _______.   expansion   energy   electricity   Half-n-half Clue   5. The calorific value of a fuel is the quantity of heat produced when a unit _______ of it is burnt.   weight   volume   mass   Half-n-half Clue   6. _______ have the highest calorific value.   Fats   Carbohydrates   Sugars   Vitamins   Proteins   Half-n-half Clue   7. Water at 20oC is mixed with an equal mass of water at 85oC. If there are no heat losses to the surroundings, then what is the final temperature of the water mixture ?   20oC   105.0oC   52.5oC   85oC   Half-n-half Clue