How microwaveoven works?

How microwave oven works?
In microwave ovens, the two important things are presence of water molecules in the respective food stuff and the production of microwaves.The microwave acts like a magnetic field while the water molecules are compared to a magnetic dipole placed in a magnetic field.We know that when a magnetic dipole is placed in a magnetic field, it produces some torque.
Similarly when microwave is passed through the food stuff, the water molecules in the stuff reacts to release some energy, which is acquired by other particles in the food stuff leads to cooking of the food.

In the fig. the green lines indicates the microwaves, thus the watermolecules reacting to it.
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Aeroplane's take off

What is the principle behind the airplane's take off?

  It is what the Bernoulli's principle. Bernoulli's Principle states that as the speed of a moving fluid increases, the pressure within the fluid decreases.

The same principle served as the base for the manufacture of air crafts.

You can see that airplane's wings are made in such a way so that the velocity of air in upper portion is greater than the lower portion.This high velocity in the upper portion leads to lower pressure, while the lower velocity in the lower part of the wing leads to greater pressure when compare to the upper part.This pressure in the lower portion lifts the wings of the plane and so that of the plane.