6.A glass bulb is balanced by a brass weight in a sensitive beam balance. Now the balance is covered by a glass-jar which is then evacuated. Then:

7.The pressure at the bottom of a tank of liquid is not proportional to:

8.An iron ball is weighed in air and then in water by a spring balance:

9.A block weighs 15 N and 12 N in air and water respectively. When it is immersed in another liquid, it weighs 13 N, then the relative density of the block is:

10.An alloy is prepared by mixing equal volume of two metals. The specific gravity of alloy is 4. But when equal masses of two same metals are mixed together, the specific gravity of alloy is 3. The specific gravity of each metal is: