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

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

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

An ideal gas at `27` degree celsius is compressed adiabatically to one fourth of its original volume. What will be the rise in temperature of the gas  ? (The ratio of molar heat capacities of the gas is 1.4 ).