State the condition under which a microwave oven heats up food item containing water molecules most efficiently.

State the condition under which V(X+ Y) = V(X) + V(Y) ?

What are the conditions under which a body can stay in a state of rest.

state the factors upon which the efficiency of a heat engine depends .

A ‘thermacole’ icebox is a cheap and efficient method for storing small quantities of cooked food in summer in particular. A cubical icebox of side 30 cm has a thickness of 5.0 cm. if 4.0 kg of ice is put in the box, estimate the amount of-ice remaining after 6 h. The outside temperature is 45 ^@C , and co-efficient of thermal conductivity of thermacole is 0.01 J s^-1.m-^1 K-^1 . [Heat of fusion of water = 335 x 103 J kg^-1

For an experiment in Botany, two different plants, plant A and plant B were grown under similar laboratory conditions. Their heigths were measured at the end of each week for 3 weeks. The results are shown by the following graph. During which week did Plant A grow most?