Someone please explain clearly regarding the polarity and the voltages so that I can Understand clearly

 

Vb is not 2V. The question is asking for VB, not Vb.

It's just arithmetic.

 

Hi,

It might help to declare one of the nodes the ground node first, then go from there.

 

It might help to declare one of the nodes the ground node first, then go from there.

That would only cause more confusion as there is no node in the circuit at 0V potential.

 

There would seem to be a particularly intimate relationship between VA and VB.

 

View attachment 138580

Someone please explain clearly regarding the polarity and the voltages so that I can Understand clearly

It might help to consider the fundamentals of typical node-subscript notation.

You have three nodes in the problem, a, b, and c.

A single node subscript refers to the voltage at that node relative to some reference point that is simply arbitrarily defined as being at 0 V.

You are given one such voltage, namely

Va = 1 V

You aren't told which point in space is at 0 V, but wherever it is, Node a is 1 V higher than that.

A double node script is merely a shorthand for the difference between the voltages on two nodes. So

Vab = Va - Vb
Vba = Vb - Va = -Vab

We also use other, non-node subscripts to refer to various voltages. In this case, the diagram defines four of them, one for each component, using the component labels, A, B, C, D.

The diagram indicates the polarity of the defined voltage, which is the positive node minus the negative node associated with that label. So

VA = Vb - Va = Vba

Now you do the same for the other three.

With these in mind, what is the value of VB?

In fact, what are all of the following: Va, Vb, Vc, VA, VB, VC, VD

 

It might help to consider the fundamentals of typical node-subscript notation.

You have three nodes in the problem, a, b, and c.

A single node subscript refers to the voltage at that node relative to some reference point that is simply arbitrarily defined as being at 0 V.

You are given one such voltage, namely

Va = 1 V

You aren't told which point in space is at 0 V, but wherever it is, Node a is 1 V higher than that.

A double node script is merely a shorthand for the difference between the voltages on two nodes. So

Vab = Va - Vb
Vba = Vb - Va = -Vab

We also use other, non-node subscripts to refer to various voltages. In this case, the diagram defines four of them, one for each component, using the component labels, A, B, C, D.

The diagram indicates the polarity of the defined voltage, which is the positive node minus the negative node associated with that label. So

VA = Vb - Va = Vba

Now you do the same for the other three.

With these in mind, what is the value of VB?

In fact, what are all of the following: Va, Vb, Vc, VA, VB, VC, VD

Thanks. Got the answer.

 

That would only cause more confusion as there is no node in the circuit at 0V potential.

True. However, "you" could draw a ground and place an independent voltage source from Va to ground, and the problem states that is voltage source is 1 volt.

 

There would seem to be a particularly intimate relationship between VA and VB.

^ what they said. No need for any math.