A) 1, 2 and 3 |
B) 1, 2, 3 and 4 |
C) 2, 3 and 4 |
D) 1 and 4 |
A) 1, 2 and 3 |
1). Paper becomes brittle and yellow with age. Why? 1. The acid content in paper causes brittleness to develop 2. In the presence of visible light, photosensitised oxidation occurs 3. The ultra-violet component of sunlight causes photolysis of cellulose by direct cleavage of the cellulose polymer
| ||||
2). Water kept in an old 'surahi' is less cold than the water in a new one. Why?
| ||||
3). The best conductor of electricity is :
| ||||
4). Which of the following is the correct sequence of the regions of the sun as one moves from its core to the surface? 1. Photosphere 2. Chromosphere 3. Convection zone 4. Corona
| ||||
5). You are standing in a lift. The force on the floor of the lift due to your weight will:
| ||||
6). If earth were 3 times as far from the sun as it is now, how would the gravitational attraction compare with its present value?
| ||||
7). Two cars, passing each other at high speed, are in danger of side swiping because :
| ||||
8). What is the correct ascending order for frequencies of the following radiations? 1. Visible 2. X-rays 3. Ultraviolet 4. Radio Waves
| ||||
9). Nuclear fission is caused by the impact of :
| ||||
10). Which of the following is used as a coolant in nuclear reactors?
|