If dirt and grease were good conductors of electrical current, then we could make wire
out of dirt and grease instead of expensive copper. Sadly, they're not. So a coating of
dirt and grease on the wire can have a substantial impact on the connection, and can
even block the flow of current across the connection completely. Moreover, in the case
where the ends of the wires are to be soldered, solder does not adhere to dirty wire.
I am not so sure about this it is too difficult
Answer:
During a total lunar eclipse, the moon and sun are on the exact opposite sides of the Earth, leaving the moon entirely in the Earth's shadow. During a partial lunar eclipse, only part of the moon is in the Earth's shadow.
Explanation:
Answer:
When an object is balanced, about a pivot, the total clockwise moment must be equal to the total anticlockwise moment about that pivot.
Hope that helps.