A vertical wire fixed at one end is stretched by a load of 20 Newton at lower end extension is `3**10^- is3\ m`,  is cross sectional area of wire is `2**10^-6\ m^2`,  and original length of wire is 2 metre.  Asssuming Hookes law to hold, molecular potential energy of stretched wire is

Bread mould is the name of 

A vertical wire fixed at one end is stretched by a load of 20 Newton at lower end extension is `3**10^- is3\ m`,  is cross sectional area of wire is `2**10^-6\ m^2`,  and original length of wire is 2 metre.  Asssuming Hookes law to hold, molecular potential energy of stretched wire is

Two pot are identical except that in one case the flat bottom is of aluminium and in the other it is copper. Each pot contains the same amount of boiling water and sits on a heating element that has a temperature of 150 degree centigrade. In the aluminium pot, the  water boils away completely in `520\ s`.  How long does it take for the water in the copper bottom pot to boil away completely. The thermal conductivity of aluminium and copper are `240 Js^-1 m^-1k^-1` and `390\ Js^-1 m^-1k^-1`.