Question

Can anyone help me out with this?​

Answer 1

Topic

Electricity

Concept

Kirchhoff's Current Law / Junction Rule

The sum of currents flowing into a junction is equal to the sum of currents flowing out of that junction.

We use algebraic addition rule in Junction Rule not vector addition as current is scalar quantity.

Solving

So, as per the Junction Rule,

Incoming Current = Outgoing Current

5A + 2A + 7A = i + 3A

14A = i + 3A

11A = i

So, the value of i = 11 A.

Answer

The value of current 'i' in the given circuit is 11 Ampere that is D option.

Learn More :-

SI Unit of Current is Ampere.

Dimension of Current is I.

Current is measured with the help of ammeter.

Direction of current is checked with the help of galvanometer.

Answer 2

Even though direction is associated with current, current doesn't qualify as a vector as it fails to oblige vector laws of addition.

Now,

We observe that three branches with magnitudes 2A, 5A and 7A are moving to converge at a same position while another branch of magnitude 3A is moving in the opposite direction.

Here,

Through the branch 2, net current = 5 - 3 = 2A

Through branch 1, current =7A

Through branch 3, current = 2A

Thus,

$\longrightarrow$ i = 7 + 2 + 2

$\longrightarrow$ i = 11A

Option (D) is correct.