Answer:

Explanation:
= Mg ion = 
= F ion = 
q = Charge of electron = 
r = Distance between ions = 
k = Coulomb constant = 
Electrical force is given by
![F=-\dfrac{kq_1q_2}{r^2}\\\Rightarrow F=-\dfrac{8.99\times 10^9\times 2\times 1.6\times 10^{-19}\times -1\times 1.6\times 10^{-19}}{[(0.072+0.133)\times 10^{-9}]^2}\\\Rightarrow F=1.09527\times 10^{-8}\ N](https://tex.z-dn.net/?f=F%3D-%5Cdfrac%7Bkq_1q_2%7D%7Br%5E2%7D%5C%5C%5CRightarrow%20F%3D-%5Cdfrac%7B8.99%5Ctimes%2010%5E9%5Ctimes%202%5Ctimes%201.6%5Ctimes%2010%5E%7B-19%7D%5Ctimes%20-1%5Ctimes%201.6%5Ctimes%2010%5E%7B-19%7D%7D%7B%5B%280.072%2B0.133%29%5Ctimes%2010%5E%7B-9%7D%5D%5E2%7D%5C%5C%5CRightarrow%20F%3D1.09527%5Ctimes%2010%5E%7B-8%7D%5C%20N)
The attractive force is 
Answer:
(B) at the middle of the pipe
Explanation:
In the case of an open pipe which vibrates in fundamental mode, an anti-node is formed at the middle of the pipe, here the amplitude of the wave is maximum. Hence, the pressure variation is also maximum at the middle.
Answer:
The induced voltage in the Secondary is 18 volt.
Explanation:
Given that,
Voltage = 120 volt
Number of turns in primary = 500
Number of turns in secondary = 75
We need to calculate the induced voltage in the Secondary
Using relation number of turns and voltage in primary and secondary

Where,
= Number of primary coil
= Number of secondary coil
= Voltage of primary coil
= Voltage of primary coil
Put the value into the formula



Hence, The induced voltage in the Secondary is 18 volt.
The current in a parallel circuits is not constant throughout the circuit. It varies in each path of a parallel circuit. The components that is place across each other have the same voltage in a parallel circuit. Remember, V=RI.