Answer:
The Moment of a force is a measure of its tendency to cause a body to rotate about a specific point or axis.
When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.
Answer:

Explanation:
Given that
Temperature of warm water ,T₁ = 25 °C
Temperature of cold water ,T₂ = 5 °C
The maximum possible efficiency of any heat is will be same as the efficiency of the Carnot heat engine.Therefore the maximum efficiency of OTEC system is given as follows
T should be Kelvin scale
Now by putting the values


Therefore the maximum efficiency will be 0.067 or 6.7%.