Water boils at 100°C at normal pressure of 1 arm or 100000 Pascal. Boiling temperature increases with the increase in pressure above the liquid surface. When we cook food in pressure cooker, the pressure increases due the retention of vapour and hence the boiling temperature increases in the pressure cooker upto 125°C As food is cooked at higher temperature than 100°C , it is cooked faster in the pressure cooker.
Which is always constant for a machine of given design: MA or VR ? Ans: VR remains constant for a machine of given design as it depends on the distances moved by the load and effort but MA can vary due to the friction developed between the moving parts of the machine.
Comments
Post a Comment