Using Kirchhoff's law, deduce the value and direction of the current

[haha0p1]

Homework Statement

Use Kirchhoff's law to deduce the value and direction of the current I.

Relevant Equations

Current entering a point is equal to current exiting a point

3 A+ 2 A = 7 A+ I
I = -2A
How the current can be in negative direction? If the sign if negative, doesn't it mean that the current will move towards the point P? Also If I am taking the 2A to be positive then Kirchhoff's law isn't satisfied as 5A≠7A

 

[PeroK]

Homework Statement:: Use Kirchhoff's law to deduce the value and direction of the current I.
Relevant Equations:: Current entering a point is equal to current exiting a point

3 A+ 2 A = 7 A+ I
I = -2A
How the current can be in negative direction? If the sign if negative, doesn't it mean that the current will move towards the point P?

The arrow on the diagram indicates the positive direction for current $I$. It's doesn't imply the current itself is in the positive direction.

 

[haha0p1]

The arrow on the diagram indicates the positive direction for current $I$. It's doesn't imply the current itself is in the positive direction

Even If I take the value of I to be 2 A, Still my current entering the wire and current exiting the wire is not the same as 3+5=7+2
And 5≠9

 

[PeroK]

Even If I take the value of I to be 2 A

Why would you do that?

 

[haha0p1]

Why would you do that?

Because The question is asking to find value of I which is coming 2

 

[PeroK]

Because The question is asking to find value of I which is coming 2

$I \ne 2$ as you yourself have already established. And, you seem to know that $I = -2$ but have decided that current must be positive. That puts you in an impossible position in this case.

 

[PhDeezNutz]

think of it this way:

If you designate a current leaving a node as positive and it mathematically turns out negative via KCL then that current is actually entering.

What’s really happening is that

3A is entering from the right
2A is entering from the bottom
2A is entering from the left

7A is leaving from the top