Question

Fill in the blanks:
6. To reduce fluid friction objects are given special shape called the

_________.

7. The frictional force exerted by fluids is called _____________.

8. _____________ is used in table salt to prevent goitre.

9. Complete combustion of most of the fuels produces _________which is

responsible for global warming.

10. Increasing concentration of greenhouse gases leads to

_______________.

11. Water which is suitable for drinking is called ____________.

12. The ray of light that gets reflected from the mirror is called

______________.

13. The _________ is the most common non-optical aid used by visually

challenged people.

14. The temperature at or above which a substance starts burning

_____________.

15. 3Fe+4H20-________________.

16. X and Y chromosomes are called as_____________.​

Answer 1

Answer:

6. streamlined shapes

7 drag.

8. Iodine

9. Carbon dioxide

10.  a positive climate forcing, or warming effect.

11. portable water.

12. reflected ray

13. visual aids, tactual aids

14. ignition temperature.

15. Fe3O4 + 4H2

16.  sex chromosomes

Explanation:

6.A fluid friction is the frictional force, exerted by fluids, against a moving object. Objects moving in fluid surface the fluid friction which opposes their motion. So to reduce the fluid friction Objects moving in fluids must have special shapes called streamlined shapes

7. This frictional force is called drag force, and this parallels the motion of the body in a fluid medium.

8. Iodine is used in table salt to prevent Goitre.

9. During complete combustion carbon and hydrogen combine with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O).

10.An increase in the atmospheric concentrations of greenhouse gases produces a positive climate forcing, or warming effect.

11. Drinking water, also known as potable water, is water that is safe to drink

12. The ray of light which is sent back by the mirror from the point of incidence is called reflected ray.

13. Non-optical aids include visual aids, tactual aids (using the sense of touch). auditory aids (using the sense of hearing) and electronic aids.

14. temperature at which a substance starts burning is called ignition temperature.

15. 3Fe + 4H2O ⎯→ Fe3O4 + 4H2

16. Humans have an additional pair of sex chromosomes for a total of 46 chromosomes. The sex chromosomes are referred to as X and Y