question_answer

Which of the following statements is false?    [JEE Main 2017]

A) A rheostat can be used as a potential divider

B) Kirchhoff's second law represents energy conservation

C) Wheatstone bridge is the most sensitive when all the four resistances are of the same order of magnitude.

D) In a balanced wheat stone bridge if the cell and the galvanometer are exchanged, the null point is disturbed.

Correct Answer: D

Solution :

[d]

[a]

On interchanging Cell & Galvanometer.

On balancing condition

\[\frac{{{R}_{1}}}{{{R}_{3}}}=\frac{{{R}_{2}}}{{{R}_{4}}}\]                                   .

On balancing condition

\[\frac{{{R}_{1}}}{{{R}_{2}}}=\frac{{{R}_{3}}}{R}\]

As we see both equation [a] & [b] are same. So

4th statement is false.