During blood transfusion the needle isinserted in a vein where the gauge pressure is 2000 Pa. At what height must the blood container be placed so that blood may just enter the vein ? [Use the density of whole blood from Table 10.1],

Air entering the lungs ends up in tiny sacs called alveoli.From the alveoli, the oxygen diffuses into the blood. The average radius of the alveoli is 0.0050 cm and the air inside contains 14 per cent oxygen. Assuming that the pressure in the alveoli is 1.0 atm and the temperature is 37^(@)C , calculate the number of oxygen molecules in one of the alveoli.

Each question contains STATEMENT-I(Assertion) and STATEMENT-2(Reason).the statement carefully and mark the correct answer accoring to the instrution given below: STATEMENT - 1 : If red blood cells wrer removed from the body and placed in pure water, pressure inside the cell increases. STATEMENT - 2 : The concentration of the salt content in the cells increases.

Observe the following facts : (1) The distance from the Earth to the Sun is 149,600,000,000m (2)The speed of light is 300,000,000 m/sec. (3) Thickness of class VII Mathematics book is 20mm (4) The average diameter of a Red Blood cell is 0.00007mm. (5) The thickness of human hair is in the range of 0.005 cm to 0.01 cm. (6) The distance of moon from the Earth is 384,467,000 m. (approx.) (7) The size of a plant cell is 0.00001275m. (8) Average radius of the Sun is 695000km. (9) Mass of propellant in a space shuttle solid rocket booster is 503600kg (10) Thickness of a piece or paper is 0.0016cm. (11) Diameter of a wire on a computer chip is 0.000003m. (12) The height of Mount Everest is 8848m. There some large number like 150,000,000,000m and some every small numbers like 0.000007m. Identify very large and very small numbers from the above facts and write them in the adjacent table.