If galvanometer and battery are interchanged in balanced wheatstone bridge, then

Options

A. the battery discharges
B. the bridges still balances
C. the balance point is changed
D. the galvanometer is damaged due to flow of high current.

Answer

To solve the problem of what happens when the galvanometer and battery are interchanged in a balanced Wheatstone bridge, we can follow these steps:

### Step 1: Understanding the Wheatstone Bridge
A Wheatstone bridge consists of four resistors arranged in a diamond shape. The bridge is balanced when the ratio of the resistances in one branch is equal to the ratio of the resistances in the other branch. Mathematically, this is represented as:
\[ \frac{P}{Q} = \frac{R}{S} \]
Where P, Q, R, and S are the resistances in the respective arms of the bridge.

### Step 2: Condition of Balance
In a balanced Wheatstone bridge, the condition can also be expressed as:
\[ P \cdot S = Q \cdot R \]
This means that there is no current flowing through the galvanometer when the bridge is balanced.

### Step 3: Interchanging the Galvanometer and Battery
When we interchange the galvanometer and the battery, the new configuration will still consist of the same resistances P, Q, R, and S, but the battery will now be connected where the galvanometer was, and vice versa.

### Step 4: Analyzing the New Configuration
In the new configuration:
- The battery is connected across the points where the galvanometer was.
- The galvanometer is connected across the points where the battery was.

### Step 5: Checking the Balance Condition
Even after the interchange, the ratio of the resistances remains the same:
\[ \frac{P}{R} = \frac{Q}{S} \]
This implies that:
\[ P \cdot S = Q \cdot R \]
Thus, the bridge remains balanced.

### Step 6: Conclusion
Since the balance condition is still satisfied after interchanging the galvanometer and battery, we can conclude:
- The bridge is still balanced.
- There will be no current through the galvanometer, hence no battery discharge.
- The balance point remains unchanged.

### Final Answer
- The bridge is still balanced.
- There is no battery discharge.