Question

Ra and Rd are the opposite arms of a Wheatstone bridge as are Rc and Rb. The source voltage is applied across
Ra and Rc. When the bridge is balanced which one of the following is true?​

Answer 1

Given that,

$R_{a}$ and $R_{d}$ are the opposite arms of a wheatstone bridge as are $R_{c}$ and $R_{b}$.

Suppose, the conditions are following

(a). The potential difference across the A to B and A to D are not equal.

(b). The potential differences across the B to C and C to D are not equal.

(c). The potential difference across the galvanometer is zero.

We know that,

The balance condition of wheatstone bridge is defined as,

According to wheatstone bridge

$\dfrac{R_{a}}{R_{c}}=\dfrac{R_{b}}{R_{d}}$

Where, $R_{a}$, $R_{d}$ and $R_{c}$, $R_{b}$ are the opposite arms of wheatstone bridge.

We need to find the true statement

Using wheatstone bridge,

When the wheatstone bridge is in balance then the potential difference across point A to B and A to D are equal and the potential difference across point B to C and C to D are equal .

If the bridge is balance then the voltage and current between A and C will be zero.

Hence, The potential difference across the galvanometer is zero.

(c) is true.