Question

Figure shows an unbalanced Wheatstone bridge. What is the direction of conventional current between B and D?

Answer 1

Hint: In this question, we will see the basics of a Wheatstone bridge; this will help us to get the required answer. Further, we will study about the basics of a simple circuit. We will also see the difference between the parallel circuit and series circuit, for better understanding.

Complete step by step solution:
As we know, the Wheatstone bridge circuit is two simple series-parallel arrangements of resistances connected between a voltage supply terminal and ground producing zero voltage difference between the two parallel branches when balanced.
When we see from the given figure, we observe that:
If we remove Resistance R, then we can see that the potential difference across the terminal AD is less than that across terminal AB.
 So, we can say that the potential of D is higher than that of B.
Now, when we connect Resistance R, as we know that the current will go from higher potential to lower potential, i.e., from D to B.
Therefore, we get the required answer that the potential will go from D to B.

Additional information:
We should know that in a series circuit, the output current of the first resistor flows into the input of the second resistor; so, the current is the same in each resistor whereas In a parallel circuit, all of the resistor are on connected together on one side and all the leads on the other side are connected together.
In a circuit if the resistance is constant over a range of voltage, then I = V/R, can be used to predict the behavior of the material. This involves DC current and voltage, it is the same for the resistors. Further, a material obeys Ohm's law or does not obey; the resistance of the material can be described in terms of its bulk. The resistivity, and the resistance both, is temperature dependent. Over certain ranges of temperature, this temperature dependence can be predicted from resistance.

Note:
In series connection the resistances are directly added whereas in parallel connection resistance is added inversely. Internal resistance of a circuit refers to the opposition to the flow of current offered by the cells and batteries themselves thereby, resulting in the generation of heat. Internal resistance and resistance both are measured in Ohms.