Which law of thermodynamics states that heat naturally flows from a hotter body to a cooler body?

Which law of thermodynamics states that energy cannot be created or destroyed only converted from one form to another?

What is the SI unit of frequency?

What is the unit of power in the SI system?

Which phenomenon occurs when light bends around the edges of an obstacle or aperture?

Which property of a body is measured by the amount of matter it contains?

What is the process by which a solid changes directly into a gas without passing through the liquid phase?

What is the SI unit of energy?

What type of lens is thicker at the centre than at the edges?

Which law states that the current through a conductor is directly proportional to the voltage across it?

Which colour of visible light has the longest wavelength?