Answer:
1. Battery
2. Copper wire
3. Nail or piece of metal (zinc, iron, or steel).
Answer:
I think it's 0 N 3rd choice
Answer:
Both are examples of negative feedback regulation.
Explanation:
The maintenance of the homeostasis in the body is controlled by the the feedback regulation of the body. Two main types of feedback regulation are positive regulation and negative regulation.
The negative regulation occurs when the final product of the reactions inhibits the further secretion of that product. In the given examples of aldosterone and calcium mechanism, the secretion of aldosterone and calcium decreases as the normal levels are acheived in the body.
Thus, the answer is both are examples of negative feedback regulation.
Answer:
The new potential energy decreases by the factor of 2 to the old potential energy.
Explanation:
Capacitance of a parallel plate capacitor is given by the relation :
C = (ε₀A)/d
Here ε₀ is vacuum permittivity, A is area of the capacitor plate and d is the distance between them.
Potential energy of the capacitor, U = 
Here V is the potential difference between the plates.
According to the problem, the distance between the plates get double but area remains same. So,
d₁ = 2d
Here d₁ is new distance between the plates.
Hence, new capacitance is :
C₁ = (ε₀A)/d₁ = (ε₀A)/2d = C/2
The capacitor have same potential difference that is V. Hence, the new potential energy is :
U₁ =
= 
U₁ = U/2

Answer: Its The Force Of Gravity
I hope this helps :)