Which of the following statements is FALSE? A. In a balanced Wheatstone bridge, if the cell and the galvanometer are exchanged, the null point is disturbed. B. A rheostat can be used as a potential divider. C. Kirchhoff's second law represents energy conservation. D. Wheatstone's bridge is the most sensitive when all the four resistances are of the same order of magnitude.

Step-by-step solution

In a balanced Wheatstone bridge, the condition for zero deflection in the galvanometer is P Q = R S . If the cell and the galvanometer are exchanged, the new condition for balance becomes P R = Q S , which is mathematically identical to the original condition. Therefore, the bridge remains balanced and the null point is not disturbed. Statement A is false. A rheostat can be used as a potential divider by connecting the source across its fixed terminals and taking the output across one fixed terminal and the variabl