Answer:
current going into a junction in a circuit is EQUAL TO the current comming out of the junction.
Explanation:
Krichhoff's Current Law
Kirchhoff's current law (1st Law) states that current flowing into a node (or a junction) must be equal to current flowing out of it.
Explanation:
It is given that,
Total weight of the piston, W = F = 70 N
Area of the piston, 
Let P is the pressure exerted on the piston by the gas. The force per unit area is called the pressure exerted pressure of the gas. Mathematically, it is given by :



We know that the atmospheric pressure is given by :

So, the pressure is given by :



Hence, this is the required solution.