1. Which one of the following was used as a chemical weapon in the first world war?
A. Hydrogen cynaide
B. Mustard gas
C. Water gas
D. Carbon monoxide
2. What is “Smog”?
A. A liquid particle resulting from vapour condensation
B. A solid particle, e.g. flyash
C. A combination of smoke and fog
D. Nothing but black smoke
3. Which of the following process does not evolve carbon dioxide in air?
B. Organic decay
4. Which is the largest flightless bird?
5. Species listed in red data book are—
D. All of the above
6. Stethoscope was invented by—
B. Rene Laennec
C. Louis Pasteur
7. Amount of energy transfered from one trophic level to next is—
8. When a CD (compact disc used in audio and video systems) is seen in sunlight. Rainbow like colours are seen. This can be explained on the basis of the phenomenon of –
A. Reflection and transmisssion
B. Reflection and diffraction
C. Refraction, diffraction and transmission
D. Diffraction and transmission
9. Why is red light employed for danger signals?
A. Red light is scattered most
B. Red light is scattered least
C. Human eye is most sensitive to red colour
D. Red colour is soothing to the eye
10. Which one of the following phenomena cannot be attributed to the refraction of light?
C. Twinkling of stars