The specific latent heat of vaporization of a substance is always?
PQ is a thin rod on a horizontal table, RS is a plane mirror inclined at \( 45^{\circ}C\) to the horizontal as shown above. The image of PQ as seen in the mirror by the eye T is
the image above shows an inverted U-tube with the open end, O of one limb below the level, W of water in the tank, in order that water should begin to flow from the tank it is is necessary that
