Name a device or gadget that converts a) Heat energy to mechanical energy b) heat energy to light energy
c)electrical energy to sound energy

How do i solve this physics problem?

X-ray crystallography is used to see the structure of molecules. scientists have used the technique to find the structure of cholesterol an important biological molecules knowledge of a structure of cholesterol is because it may affect?

The resistance of 100 w bulb is less than resistance of 40 w bulb. explain the reason.