61). Cryogenic engines find applications in :
| A). rocket technology |
| B). frost-free refrigerators |
| C). sub-marine propulsion |
| D). researches in superconductivity |
|
62). Which of the following take place when the subject speaks untruth while being tested by the polygraph instrument?
1. His blood pressure goes up.
2. His pulse quickens
3. His skin darkens
4. He sneezes
| A). 1 and 2 |
| B). 3 and 4 |
| C). 1, 2 and 3 |
| D). 2, 1 and 3 |
|
63). If S denotes sound energy, E denotes electrical energy and M denotes magnetic energy, the correct representation of recording and reproduction in an audio tape recorder is :
| A). S-->M-->E-->M-->S |
| B). S-->E-->M-->E-->S |
| C). E-->S-->M-->S |
| D). E-->M-->E-->S |
|
64). In a refrigerator, cooling is produced by :
| A). the ice which deposits on the freezer |
| B). the sudden expansion of a compressed gas |
| C). the evaporation of volatile liquid |
| D). none of these |
|
65). The best colour(s) for a sun umbrella will be :
| A). black |
| B). black on top and white on the inside |
| C). White on top and black on the inside |
| D). printed with all the seven colours of rainbow |
|
66). Which of the following laws is explained by the statement that matter can neither be created for destroyed?
| A). Law of Conservation of Energy |
| B). Le Chatelier's principle |
| C). Law of Conservation of Mass |
| D). Law of Osmosis |
|
67). The mass-energy relation is the outcome of :
| A). Quantum theory |
| B). General theory of relativity |
| C). Field theory of energy |
| D). Special theory of relativity |
|
68). The following processes take place during the launching of a rocket :
1. Rocket fuel is burnt.
2. Gases are produced.
3. Rocket moves in the forward direction.
4. Gases come out with momentum in backward direction.
The correct sequential order in which the above processes occur, is :
| A). 1, 2, 3, 4 |
| B). 1, 3, 2, 4 |
| C). 1, 2, 4, 3 |
| D). 1, 3, 4, 2 |
|
69). To achieve high value of rocket velocity, one must have :
| A). high exhaust velocity and low loss of mass during propulsion |
| B). high exhaust velocity and higher loss of mass during propulsion |
| C). low exhaust velocity and higher loss of mass during propulsion |
| D). none of the above |
|
70). Aviation fuel for jet aeroplanes consists of purified :
| A). petrol |
| B). kerosene |
| C). gasoline |
| D). diesel |
|
